Another (largely unheard-of) alternative to Notion is https://www.larksuite.com/ , by ByteDance. It's quite good.

(I hope I didn't just start a political / ideological debate because I mentioned ByteDance.)

Not sure why you would think it'll reach geopolitical level, a good product is a good product.

But, based on the description in their Chinese page, the service is not self-hostable (???). If this is true then there is no real reason to use such service since there are many better alternatives (Notion for example).

Does not seem to be Open Source or offer a self host option like AppFlowy.

It's not like Notion's privacy policy/TOS are great to begin with, so it's a low bar.

This doesn't look much like Notion. I think it's a lot closer to something like Google Suite (even the name indicates that).