sigh If data brokerages, Meta, Google, and Palantir are all staring at you how is it possible to claim privacy is even possible? Like, you have to have a thing before it's possible to assault it.
So having established one would have to institute I'm-hiding-from-at-least-two-sovereign-governments-that-are-actively-hunting-me levels of OPSEC to even stand a chance of avoiding being thoroughly fingerprinted I'm fairly confident in my point is proven here. I don't see anyone proposing to gut Meta and Google's business models, ban data brokerages, or any of a myriad other possible things that would at least in theory result in the possibility of actual online privacy. What I'm seeing is folks screeching at the prospect of a legal framework by which these companies negative impacts on kids might be managed. And of course literally no alternatives are proposed to address said harms in lieu of requiring ID so here we are.
You're attacking a strawman, there are definitely alternatives such as mandating a protocol for describing content that parent-controlled content policies in user agents would key off of. I mean even today you can just ban instagram on your kid's phone. Regarding futility of trying to preserve privacy, I'm not sure if you're aware that Apple doesn't have much of a standalone service business and it's widely deploying OHTTP, anti-fingerprinting, etc. Obviously they moderate their efforts to not push too far, too fast, yet fingerpriting a mobile user on iOS is not trivial.