Noo

Name, address, GPS localisation data, habits (like apps you often use, moments you use one device or another), gender, search terms in search engines, open web pages on a web browser, connection (other person you know), the work you do and where you work.

All kinds of things, really.

The usage is mostly advertising or identity theft.

Maybe this: https://tournesol.app/ could be of some help ?

Indeed, see difference between libre software and open source software.

Just play games you like, you can play most multiplayer games with randoms without chatting or talking. You will probably miss some fun, but it’s not a big deal I assure you.

Just play the game you want to play, you’re not the only one who does it without talking online (like me).

Indeed, that’s why I talked about Yunohost. Nextcloud install is just one click button on Yunohost.

Archive.org if you are looking for a public place.

If you are looking for private use, I would recommend taking a small/old PC and run Yunohost with Nextcloud.

Also all depend on the stuff you’re talking about…

Son you didn’t have class manuals?