Most Git users will never have more than one remote per project, and so will only have a single product built from their source code. Probably wouldn't even know how to configure their mua to send text-only emails, in case that option is even available to them, and would struggle with basic Unix utilities like Vim and diff.
I don't know why Git won the VCS contest. But, I'm afraid, as with many such wins, there wasn't a clear rational reason why it should have won. It didn't make some of the obvious bad decisions which would disqualify it, but so did a few others. My take on this is that communication tools naturally gravitate towards monopoly, so, if one starts to win even slightly, the win will become a landslide win.