> but the internet today has a lot more pedos and groomers online than in the 90s

Without some data analysis I honestly don't know. Even before Internet (ex: FidoNet) there was plenty of very bad stuff out there, I don't see any clear reason why the pedos and groomers would have avoided it.

> We have to separate kids from adults on the internet somehow

I think what is much worse than in other mediums is the actual lack of a community that observes. In real life, for many cases, you would have multiple people noticing interactions between kids and adults (sports, schools, parks, shops, etc.), so actions might be taken when/before things get strange. On some of the social networks on the internet it is too much one-to-one communication which avoids any oversight.

So, for me, the idea of "more separation" seems to generate on the long term even more problems, because of lack of (healthy) interactions and a community.