The US is behind other democracies which have required photo id for social media and other content. And even if I disagree with these laws, surely you jest that showing a proof of age is not the same thing as surveilling and scoring.

These things are always a slippery slope. They rarely, if ever, achieve their safety goals but they almost always achieve the goals of the corporate interests to garner further data for advertisers and increase surveillance of the populace by the government through proxies that buy said data and then sell to the government.

I think the general assumption is that it only aids in surveillance.

It is not merely showing proof of age

It is using the proof of age requirement to require a much larger ask -- full proof of identity

Age verification could be done with any of a variety of mathematical systems showing you have a proven age-valid ID but not revealing your identity. But no one is suggesting they build and use such a system.