99.99999% of projects are not the Linux kernel, so how could Git have succeeded because of Linus, other than Linus originating the genius design of it? The Ruby community jumped onto Git even though there was no Github, and Ruby itself didn't use Git. In my opinion it was because Git was the first tool that was superior to SVN in every way.

The first time I used Git I swore I would never use SVN again. It was even popular back then to set up git+svn systems so you could work on your git repo, and push a branch to svn to satisfy your employer.

People associate git with Github (and Gitlab), but it used to be very common to just set up a ssh server that people could push projects on to, my server still has a dozen or so projects on it that I haven't touched in a decade. Github spawned from the popularity of Git in the Ruby community, and the desire to make it a little more accessible to people that didn't want to have their own git servers.