In the UK we have many people on the left with these perspectives. It comes from the second-wave feminist tradition.
But generally speaking, online age verification is one of those issues where the left-right ideological divide doesn't map neatly. People support and oppose it for various different reasons. Much like the assisted suicide issue.
Age verification efforts in the US have been privacy-attacking (demanding government ID) whereas the system being proposed in europe is privacy-preserving (zero-knowledge proof).
It would be interesting to see a similar lobbying breakdown for the EU and UK. I bet it's still Meta with other right wing actors. The left rarely has the money for this kind of lobbying scale