Those were not his ideas. Before Git, the Linux kernel team was using BitKeeper for DVCS (and other DVCS implementations like Perforce existed as well). Git was created as a BitKeeper replacement after a fight erupted between Andrew Tridgell (who was accused of trying to reverse engineer BitKeeper in violation of its license) and Larry McVoy (the author of BitKeeper).

https://graphite.com/blog/bitkeeper-linux-story-of-git-creat...

You may find this 10-year-old thread on HN enlightening, too: https://news.ycombinator.com/item?id=11667494