Earlier quoted context omitted.
Idk if git was designed to not be used in a centralized way. Like all other common CLIs, it was simply designed to work on your PC or server without caring who you are, and nothing stopped a corp from turning it into a product. Torvalds made git and Linux, then he put Linux on Github.
It's not a "CLI" and yes, "decentralized" was literally one of the points of it.
It's like, a Redis cluster is distributed but not decentralized. The ssh protocol is not decentralized. XMPP, Matrix, and Bitcoin are decentralized protocols, first two via federation.