I don't know, I'm all for keeping people away from addictive behaviors and would rather micro transactions not be a thing at all full stop - but allowing users to get money out of games they have already invested in is also a benefit, so it feels weird to single out the one option that provides consumer value. Don't play CS anymore? Sell the AK Fire serpent you unboxed for 2.50 back in 2014 and buy yourself a steam deck and keep a gift card for a few games. Or a new set of skins in whatever game your playing now is.

As far as the API goes, Im pretty unfamiliar so Im not sure what responsibilities a company has when using their site as a login to another site. There's porn sites that allow me to sign in with Facebook / Gmail, if someone uploads CSAM to that site do those sites have a duty in some way?