You can of course have secure id checking without data protection laws: the companies doing the check can just not store information about the check, regardless of whether they are required to delete it. As long as they are not required to retain it, which I have not seen anywhere, they certainly can choose not to. Here though, the laws I've looked at all specify that they must not retain it. They could have higher penalties, but they already explicitly forbid it.

Like I said several times and have said in other similar threads, I'm inclined to think RTA headers are a "better" approach. Currently they're not consistently implemented on either end (e.g. Firefox doesn't support them, sites I mentioned don't send them), but it'd be a quick win to mandate that in commercial contexts, which would include Firefox.

But you don't have to look far to find people who think the filtering problem is entirely intractable (they're in this thread). I think it's worth trying the metadata approach more with commercial mandates to implement something along those lines. I can see why people could argue that's been tried enough (filters have existed for over 20 years, and access for children is still easy), and they need something more. It's not clear that they're even wrong, though I'd like to see us try still. But the more I consider it, it really doesn't seem like that big of a deal to just do ID checks. Presumably you'd do it once to establish an account that's above the age limit. Not the end of the world.

Maybe I'm wrong about these sites' lobbying efforts. Maybe most of them have been posting on their front page big banners asking people to tell their representatives to support mandatory metadata processing/filter enablement laws. I sort of doubt it, but it could be. I do know that some major sites (e.g. reddit) don't implement the metadata or any other controls.

It's not clear what the "percent of content" in these laws means, but when I looked at dumps last year, reddit looked to be ~40% porn by posts (obviously not if you consider comments to be content for counting). It is (or was, as of last year, if dumps are accurate) pretty close to being more porn than not. Certainly for a discussion about how porn sites behave, they are a major porn site with millions of users, and they do exactly nothing to turn away minors (in fact they obviously target them) or segregate the site.

I pointed out elsewhere that routers can block common VPN protocols (e.g. ipsec or wireguard). Of course they can do almost nothing to block something going over TLS:443, and soon they won't be able to do SNI sniffing either. So network filtering of sites is not possible anymore unless they stop using TLS.

Anyway, my point about worrying about data collection and retention is that people should worry about it to the same extent they do with eBay or some small shopify-based site. They should worry about it! But they shouldn't specifically worry about porn sites. And the laws here seem to all ban retention, which is good. Perhaps they could have higher penalties, but they do ban it. Generally e-commerce sites don't have retention regulations.

It's not clear to me how governments would get any records to retain, but sure they should disallow it.

3rd parties already store data that can be used for verification. I don't see KYC laws being undone anytime soon. There's no need to record any information about a verification occurring. I'm sure companies offering KYC services who are already used to operating in regulated environments can deal with not retaining submitted information.

I don't really understand your point about "transactional" relationships. If you have a business providing a service, they can follow relevant laws for their industry. If total wine decided to place an unmonitored "free beer" keg out front where children could get to it, they'd almost certainly end up in legal trouble.

Or perhaps a more direct analogy would be if you opened an adult theater with an automated ticket machine so no one checked who was coming in. Or a Redbox that took cash and rented adult movies with no checks. That business would never fly in person. Why is it different online?