In any case, there is a general problem on the internet regarding how to allow people to remain reasonably anonymous while keeping children out of certain services.

The additional context here is that Google acquired them to get back Noam Shazeer and took some other members of their technical staff.

So the current company is pretty much shambling along after having served its purpose to all stakeholders, and Google probably doesn't really care more than avoiding any sort of liability.

Good, privacy preserving age check could be implemented instead, but they won't because it's not about keeping the kids away (and never was).

And your example with Instagram is great because they've been caught running experiments actively harming children.