{part 1}

I apologize for going too far here. I'm certainly bringing my own bias to bear which is worth mentioning: some relatives of mine have had their marriages blow up because their husbands were engaging in sexual conduct outside of their relationship behind my relative' backs. The amount I care about my extended family and the effect it had/has on them (especially my (step-?) nieces and nephews) certainly biases me a lot.

Sex is great, and an important part of life. I fundamentally agree that action between two consenting parties that does not affect any third parties (e.g. my relatives / their kids in the above example) is totally fine, from drugs to porn to swingers or anything else. Even though I prefer monogamy, I don't think it's some societal downfall if people engage in activity I wouldn't participate in myself.

However, I think it's hard to deny biology, specifically brain development in children and the effects of porn and (separately) the drive to reproduce.

Brain development: I find this disconnect between people who are roughly >35 years old and those who are younger: men in the latter category grew up having access to unlimited video porn on the various "tube sites" since their preteen years, whereas in the former category these tube sites are something one likely stumbled upon as in early adulthood or later. Exposure to this type of pornography (vs. something like a VHS tape or a playboy issue) in the younger cohort, specifically for men, is very different from the older cohort's experience; whereas the older group learned about their sexuality in an environment that was not very different from that of prior generations, the younger group received (and receives) a level of stimulation through these tube sites that wires their brains differently at a formative point in their lives (roughly, the teen years). The unlimited, unfiltered exposure to every type of sexual act under the sun, without context or education, influences how the younger cohort (especially men) views sex. Consensual sex, be it swinging or porn or anything else, is not what is taught; porn tends to portray that sexual acts are about self-fulfillment, not mutual fulfillment. I say "tends to" because I must admit I don't know about the myriad categories that must exist now, but I'm guessing the category of "person A and person B do [some sexual act] and then cuddle while expressing their love for each other and discussing their future plans" is not near the top of that list.

Reproduction drive: the drive to procreate is hard-wired as one of, if not the most important aspects of all animals, and the human brain is built upon a very deep animal "core" (Thinking, Fast and Slow [0] gives a good deal of evidence about the ancient and modern brains). That proclivity, combined with the ease of access to porn, creates a problematic situation. The things you mentioned are either a) difficult to access or have legal consequences (e.g. cocaine) but have a strong influence on one's neurology or b) easy to access but are less prone to activating some primal drive inadvertently (e.g. lawn mowing, baseball cards, though I'm sure even something like baseball cards can become an addiction). Porn falls into both categories. This ease of feeling good or relieved through porn can definitely cause addiction (see all of the nofap stuff on reddit or on other forums).
The desire to exchange money for instantly feeling like someone desires you, up to and including in a sexual way (i.e. through prostitution, or perhaps some very intimate only fans interaction), can certainly drive men to eagerly lust after such options if the only other option is to face up to the hard facts about one's choices or shortcomings in life (although I posit that this latter action will lead to more fulfillment).

On top of all of this, you have tech companies, who have honed their suggestion algorithms to suggest the perfect video to each viewer, exploiting these neurologic drives to increase view time in order to get more ad revenue. Just as these algorithms have thrust fringe conspiracies and fear or anger inducing videos towards people on youtube, it has thrust videos that exploit the human sexual drive towards the viewers, which in turn causes more of such videos to be produced. As I stated in the paragraph about brain development, I doubt these videos encapsulate very many, if any, of the important aspects of healthy sexual interaction (e.g. open and honest discussions about what boundaries to draw, the meaning one sees in sex).

> Society is better overall when your arbitrary restrictions on what two consenting people can do is removed, as my beliefs on what should be banned are different from yours and different from the guy down the street, so it's better to default that anything that doesn't harm me and is between two consenting people is fine for them.

I agree with you that these things (drug usage, sexual acts) should /not/ be banned. Any sort of government intervention is certainly a net loss in terms of the outcome of both the individuals involved in the activity /and/ society as a whole. There are too many people in prison in the name of the war on drugs (costing money in both the short term to house them, and in the long term when counting the contributions they could have been making, not to mention the ethical malfeasance of it), Alan Turing was chemically castrated for being gay, etc. When the government gets involved in people's choices that don't harm other people, it generally ends poorly.

However, I think it's dangerous to expect that most people, especially adolescents, will successfully navigate their discovery and understanding of their sexuality and preferences when they are exposed to hypernormal sexual stimuli that tries to hijack their sexual urges to turn their watch time into profit. I don't think that these tubes sites have anyone's sexual health in mind, both the consumers and producers of the content. It sounds like you and your wife (and your swinging friends) have come to a healthy equilibrium, and that is fantastic! However, I think that's an exception, a bright light at the end of a lot of understanding and communication and potentially fraught conversations, when the rule (for almost everyone else) is secrecy and self-fulfillment.

> If you are seriously disabled, your partner has died, you are very old, or have any sort of issue that makes it impossible to have a normal sex life or have any chance of finding a partner that is young and attractive, this is certainly ethically OK to trade money for temporary sexual activity. This is a free exchange between consenting partners.

I have lived in a country with legalized prostitution, and I agree that sex work can be an important substitute for (typically men) fulfilling needs. When I was trying to learn "erotic vocabulary" in the country's language, I would actually read the text from the "escort ad / review" sites. The ads will specifically mention "pensioners / disabled welcome!" and the reviews would be almost heartbreakingly touching, like "Svetlana made me feel vibrant and youthful, in a way I haven't felt since my wife died". I agree that these transactions are beneficial to both parties and serve an important purpose (financial, emotional, physical) in both parties' lives.

However, there is a reason that the reviewers use pseudonyms and the prostitutes typically hide or blur their face in their photos on the sites: there is a social stigma against this type of exchange for both parties. This social stigma may very well close doors for one's future prospects, and pretending otherwise does a disservice to both participants. Understanding that one may make a lot of money (for women) or be able to achieve sexual stimulation with almost no effort (for the Johns) may feel good right now, but that part of one's life may very well stain one's record for future endeavors. For example, I know that anecdotes are not data, but I have not met a man or woman who would be totally okay with it if their partner would have been involved in sex work; most would consider it a deal breaker. By choosing to engage in sex work (producing or consuming), an enormous swath of potential future partners is eliminated. I don't know what kind of public awareness campaign would be needed to change public opinion on such a massive level (i.e. to become okay with sex work), but I know that whinging about how unfair it is that people have different opinions (i.e. a stigma against sex work) does not help.

It's not a judgment on the participants in an absolute sense, but pretending that there are no negative consequences in terms of the judgment they will likely receive from other people sets people up for a harsh reality shock. It's even worse when we encourage the participants to stand against the prevailing forces of human nature (i.e. all the evolutionary biology stuff), a quixotic endeavor if there ever was one.

[0] https://en.wikipedia.org/wiki/Thinking,_Fast_and_Slow