@Em0nM4stodonEm Whenever I see discussions about online ID/age verification come up, I tend to see a few people speaking up about ZKP (zero knowledge proofs). Admittedly, I know almost nothing about it, but a cursory read on the subject makes it sound like it could be a solution to the problem.

Of course, this is assuming that one takes the stated/claimed problems (e.g. protecting age-restricted spaces from those who are underage) at face value. When it's more likely that the goal of these programs is broad surveillance and control, which nobody would willingly accept if it was presented so plainly.