I also feel like many of the current guest posts have overlapping ideas and arguments and so I get less out of each one of them. Maybe a separate blog for endorsed opinion pieces would be appropriate.

Proofs and Prompts exists already and a lot of articles on Tao's blog are also duplicated there

https://proofsandprompts.com/

Well, I meant that I would rather have the "old" Tao blog with less guest posts and people who want both can also subscribe to the separate blog.

It is classic audience capture. These are more popular than his and his most polemic guest posts are frequently described as well-written by many audiences.

In some sense, it’s a simulacrum of the Internet’s forum experience - broadening one’s own audience necessitates debasing one’s content. But such is life - he now probably has for more readers than before and likely finds that pull gratifyingly attractive.