It's pushed both by those with surveillance agendas and AI companies like Anthropic, who donated millions to PACs and politicians that are pushing online age verification and surveillance laws[1].

The goal for the AI side is that they get to be censors and gatekeepers of all user-generated content on the internet, their models will rank/grade/censor content for age-appropriateness and they will have the pleasure of being paid to train on all new content uploaded to the internet in real-time, in perpetuity.

[1] https://news.ycombinator.com/item?id=47162956