> I'm pretty sure git is industry standard almost entirely entirely because GitHub exists.

Nah, I remember that time vividly, Github became a thing about a year or two after it was already very much taking the lead.

GitHub became GitHub because git was the winner. There were alternative hubs that supported bazaar and mercurial and whatnot, but git won because for most people, Linus and the kernel team being behind it was reason enough to trust it.

(and I say this as someone who liked hg more than git)

Git was blazingly fast when it came out, faster than hg (C vs Python) and of course a different order of complexity to svn, which was the actual existing alternative it supplanted.

Anyone who has ever used Mercurial knows very well what a good versioning tool UX looks like...