Replication is not enough, Competition only wins if it offers lower cost or better service (or intolerable service if free), While yes, the userbase is essential, you're still ignoring the reason why the userbase is there in the first place services before github existed and github is the one that ended up winning, competition cannot just offer a better ethical stance and its not even that, since github itself is not doing anything criminal, it's simply aligned with microsoft, so the ethical stance is "I don't like AI" and "I don't like microsoft", that is simply not enough of an offer to make the entire userbase switch. the only way you could is if github decided to throw all of its userbase like bitbucket did, and given that its name is git, I doubt they'll ever do that.