

Ok we’re talking at cross purposes.
Yes, mullvad has a noble repo, it doesnt have a xia repo (which is the mint equivalent version name)
Attempting to add the mullvad repo using the old ubuntu instructions failed because noble =/= xia
Yes you can work around that but its not beginner level.
Op asked if Flatpaks was the answer whivh imho it isnt, the best answer is downloading the .deb
https://en.m.wikipedia.org/wiki/Embrace,_extend,_and_extinguish
OP has a reasonable concern, Microsoft has had a troubling past history, and embrace extend extinguish hasn’t gone away, just look at the office file standards shenanigans.
It’s certainly the case that the purchase of github is intended to create a platform that has network effects (making it hard to leave).
Microsoft has proven many times that their participation in FOSS tends to come with a catch or an intent to subvert.