Yes, all of them if you want to. It's 100% up to you whether and how you deal with other people and their contributions, and it's completely orthogonal to being FLOSS or using a git hosting.
Then the thread feels a little tangential,
because you don’t have to “drive a hard line”, to do that,
you just draw it once (publish a no PR policy, don’t host on GH, etc),
and you shouldn’t be hearing from users.
The central freedom provided by opensource software maintainers is the fork button. Not the “merge pull request” button.
Git hosting provides discoverability and the ability to fork repositories. Everything else is an optional feature.