Yes.

For private repos there is Forgejo, Gitea and Gitlab.

For open-source: Codeberg

Yes, it'll make projects harder to discover, because you can't assume that "everything is on github" anymore. But it is a small price to pay for dignity.

Why not put open-source projects on Gitlab?

You can't create new account on Gitlab without a credit card (outside of EU and USA).

Yes, that too.