Why do you need a centralized hub? Most repos on github are entirely unrelated to eachother. Repos can be self hosted. Issues can be tracked on your own website. You don't need a megacorp to run a website. If you are writing open source tooling you are more than qualified to roll your own here.
Like the internet itself?
The internet is not centralized. It is literally the largest decentralized network in existence. A network of networks with no central hub.
Oh so you haven't heard of Cloudflare?
Cloudflare, AWS, Azure, Google Cloud and Whatever-is-used-by-China: people make fun of the IBM guy who said "the world has a market for maybe 5 computers", but he was right all along...
git on ipfs and issues stored in a literally plaintext file