Centralization is just too convenient for most people. Most people - technical or otherwise - won't accept the slightest quality-of-life (edit: and network size/activity) hit in exchange for the greater robustness of decentralized options, regardless of the application.

Note how the vast majority of people who use or interact with cryptocurrencies converge around a few centralized options. Even a ton of the technical people who develop cryptocurrency-related systems do.

The quality of life on the Fediverse is pretty good, in fact it's better than on Twitter because the default app has a lot of features from the long defunct custom clients. What people won't accept is a social network their friends aren't using.

The issue is more that p2p is always touted as the solution and yet there's been almost zero actually useful solutions developed. There's some fundamental issues preventing the decentralized network to be a generic solution and until that's sorted out, it doesn't seem to add to a conversation to bring up p2p as a solution.

You can tell when a decentralised technology becomes successful, because then someone will build something centralised on top of it.

This should be a named theorem

Git seems to work pretty well p2p without the hub.

If you don't need to collaborate with people sure it does. Everything works well until you need to collaborate.

There are numerous collaboration tools aside from Github that can be used, though.

If the project, company, or specific person you want to work with is using Github, you're using Github.

Git LFS would like a word.

There are multiple useful solutions. They are just ignored.

Notice you didn't mention any fundamental issue specifically.

The issues clearly aren't fundamental enough to stop software pirates or the Onion network.

While not a perfect solution, I think organisations like Codeberg§ are a step in the right direction.

§ https://codeberg.org/

I was thinking about this recently. What does "truly decentralized" Github look like? In particular, I'm curious about decentralized code review and so on. Probably not technically difficult or mind-blowing, but I'm curious nevertheless.