Git has always been decentralized. That was one of its purposes. Sites like GitHub, Gitlab, etc actually went against the grain and centralized them; I personally believe this helped popularize git back in the days of CVS and Subversion being the two most popular version control systems.

Git patches were made to be email friendly as a means of distributing code between developers — it’s how the Linux kernel does it (or did, I’m not up to date on their current practices).