Fair point on the plausible deniability they currently have w.r.t. children. I'm thinking more about the possibilities that open up when software can assume that OSes have this information and start gating access based on it. Once the APIs are there, I fear the internet will turn into a bunch of ID-related prompts before you can do anything. I haven't thought it through fully, but I imagine what we see as benign today like using an Adblocker could actually become more "serious" once they know your identity and can seek damages... we see companies wanting to use the legal system in Germany for example when people find a connection string in plaintext on the client instead of just fixing the security hole.

It seems like a more lucrative path to go down even if you lose the under-18 crowd gambling / watching ads on your platform.