Full stack developer and privacy advocate. I like to keep the mentality, if you can program one language well, then you can program in any language!
Hope these will help with opting out for data collection / informing yourself about it:
RedLib, the continuation of LibReddit,
still works:
https://github.com/redlib-org/redlib
I use it in combination with this GreaseMonkey script,
to redirect me to a random RedLib instance:
https://greasyfork.org/en/scripts/469587-reddit-to-libreddit-redirect
Due to instances often going down and/or stop working.
Imagine living in China,
where the government is able to request data of each company in their country.
Imagine that China would setup an AI/LLM, to feed all private chat data into it,
and automatically flagging opposition of the government regime.
Imagine a white van appearing in front of your house and disappearing into a concentration camp because you got flagged after expressing your opposition to the government to your mate in a private chat.
All collected data can be abused like that,
or by other means (E.g. a country at war gets hacked, which could lead to leaking critical private information on political/defensive decisions).
To me the question is not if data collected on you will be abused, but rather when will it be abused?
Just having it stored somewhere imposes risks.