You need to check your notes. Git is decentralized, even if you host a repository somewhere.

I am not sure if you’re wilfully ignoring my point about how centeralised GitHub is, but I’ll assume good faith:

GitHub is enshittifying everything that has to do with Git. It presents a very common pattern where nonfree software providers embrace an open standard, extend it maliciously towards a less open experience by raising capital or being acquired by a large company with massive funding then make its users trapped in many systems that make it a hard time to migrate to other places and eventually introduce anti-features and lock-in mechanisms in late stages of the software cycle.

As a Firefox user, these initiatives matter nothing in my decision to use Firefox.

You should care. As a Firefox user, you should be aware of how the funding and hiring of the people working on Firefox go. For example, most notable updates to Firefox, including Firefox Quantum, were developed in Servo, a different browser project that Mozilla completely abandoned and fired all its employees working on it, all the meanwhile in the same year the CEO gave herself a pay raise that would have paid for multiple developers to work on something proven essential to the performance and security of Firefox.