I'm quite partial to SourceHut as well but tbh I don't care about contributors and I like it because it is deliberately low-tech.

Maybe the CI could be a bit better (secrets management will sting you if you don't read the docs first), but that is also pretty no-nonsense and gets the job done.

If you like no-frills and an expectation that you know what you're doing, it's pretty sweet.

Would probably scare off most collaborators though but that, IMO, is part of the appeal. If you want to contribute then it's more likely you're invested and not driving by.

Also I like that it has a concept of projects so you can group repos together (which on GH would normally require creating an organisation account). And a repo can be public but unlisted, so it's open but not drawing attention.