Companies and governments see age verification as an opportunity to hoard data for facial recognition and other ML/AI training sets.

It will always be cheaper to go with a vendor that forces you to scan your face and ID, because they will either be packaging that data for targeted advertising, selling the data to brokers, or making bank off of using it as population-wide training datasets.

Governments will want the data and cost savings, as well.

Both corporations and governments will want to use the platforms to tie online activity to real human beings.

Arguments like these end up like arguments for PGP in email: yes, in a perfect world we'd be using it, and platforms would make it easy, but the incentives aren't aligned for that perfect world to exist.

Don't project the contemporary US administration on other countries, please. Not everyone lives in a cynical regime.