I'm on desktop now so can explain a bit more in depth. Also a minor correction. Projects are often times funded out of pocket by the creator. Though due to that nature these products cannot scale or eventually must adopt a profit model - often in the form of advertisements as it is both the laziest and one of the most successful models.

Not only will ad-driven models avoid saying anything that might harm profits - people who profit from ads are incentivized to have the ads been seen by as many Consumers as possible. The Producer/Content Creator's job is no longer to produce worthwhile content but to try and capture and retain as many eyeballs (views) as possible. Producing worthwhile content and capturing+retaining eyeballs are only loosely intertwined. The issue that presents itself later is that garbage content is both cheaper and often easier/faster to make and is also better at capturing+retaining eyeballs. So the quality of the content inevitably declines which results in issues later on for other people not only the Content Creator and the Advertiser - more on this later.

Anything that results in more views is thus encouraged by the model. Clickbait? There would still be some because some people want to go viral or be the center of attention - but most clickbait is incentivized due to the ad model. Ragebait? Same thing - incentivized by the ad model. Gamified products that give Consumers a brief hit of dopamine so they'll keep coming back for more? Incentivized by the ad model. Simplifying or watering down complex/niche content to cater to a broader audience at the expense of the original/niche audience? Incentivized by the ad model. Showing back-to-back ads? The model incentivizes showing as many ads as a user base will tolerate watching. In fact an ad model's ideal world is one where people sit and watch a channel that is nothing but 24/7 non-stop advertisements and occasionally make purchases.

Why are ads an issue? (#1) in modern times ads are often tied at the waist with invasive user tracking and (#2) Ads are rarely ever designed to enrich a Consumer's life but instead to extract value from the Consumer by convincing them to purchase a product or service even if they are not in need of the product or service. This includes abusive tactics such as making the Consumer feel worse about themselves or their lives and that buying the advertised product or service will make them feel better! Or by associating the product with good feelings. Hundreds of billions of dollars have gone into researching how to make advertisements as effective as possible - and the results of that research is that advertisements work best when they "plant seeds" in a Consumer's subconscious and bias later decisions or alter the Consumer's behavior without them ever having realized it. Issue #1 is an issue of privacy but the larger issue is that it feeds into Issue #2. The data collected is sold to other Businesses & Advertisers to better extract value by being able to target their advertisements at a more vulnerable or susceptible population.

Remember the decline of quality mentioned earlier? There is a certain level of "garbage" that the general population will not only tolerate but will choose over a higher quality product if the higher quality product comes with a higher cost. This disincentivizes producing any higher quality content if the "garbage" is acceptable enough and can be produced more cheaply. Why is investigative and long form journalism a dying art? Not necessarily that people don't want to fund it but that people don't want to fund it when they can keep getting garbage. Garbage also isn't free to produce - it's cheaper to produce. So if you can produce more garbage and the people seem to accept it - why would anyone ever spend more to earn less? You wouldn't. This applies to more than monetary costs too - time spent on creation is another factor that gets perverted. If the monetary cost to produce garbage or quality is the same but you can churn out garbage x3 faster - you're going to churn out garbage. And much like throwing stuff at the wall until something sticks - inevitably there will be some quality things that are ad funded but it will come alongside a plethora of garbage (this is a way to say "Yes, there are some rare exceptions." but you can probably only count them on your hands.)

TL;DR The ad model creates perverse incentives that harms Consumers and almost inevitably results in lower quality content by Content Creators.