A site can be a billboard for a product or service, or provide a social hub, without participating in the surveillance adtech industry. There are plenty of hobby forums, like those for craft brewing, which get supported by brewery suppliers, for example. There are luthier communities which get supported by toolmakers and professionals, and so on. The implicit community networking, reviews by community members, and other interactions reward quality and honesty, and penalize the shady shit.

It's just not scalable into the exploitative cash cows that VCs drool over.