> 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)
I mean, I don't think anyone can say for sure if "GitHub became GitHub because git was the winner" or "Git became mainstream because GitHub won the developer mindshare", pretty much everyone I knew used GitHub for everything besides the actual VCS protocol, although a lot of us early users were users of GitHub especially because of git.
Most people just wanted to collaborate on the platform other people were on, and where the popular projects were, that it used git was just an implementation detail at that point for most I think.