I dont like having 90%ish of all git repos all in one handbasket. Even if MS was benevolent, its not good to have all things in one place. A bad actor could take down all of GH and we would be screwed.

That is not how git works though. If github disappeared today it would be a lot of confusion, but the code exists everywhere it is checked out. The owner/maintainer (or anyone really) can just add a new remote and push it. If they use github specific features like issues, they would be lost though.