For complement I would recommend Russian yandex, and vk.com (russian facebook). It is like snapshot of internet from 2018, before everything was hit by massive censorship. It has some very niche communities that are no longer on internet. For example Ancient Egypt history, western net is filled with alien theories, Russians are doing experimental archaeology. Also repair, electronics...
Also Telegram is like second internet, nobody talks about!
Also Telegram is like second internet, nobody talks about!