> Git itself decentralizes source control, and yet we all want to use single-point-of-failure Github.
This is pretty much why many organizations out there, as well as i personally for my homelab use self-hosted GitLab instances: https://about.gitlab.com/
Though in practice there are a lot of other options out there, like Gitea (https://gitea.com/) and GitBucket (https://gitbucket.github.io/), though maybe less so for alternative source control systems (e.g. SVN has been all forgotten, however that's a personal pet peeve).
Not only that, but i also utilize my own Sonatype Nexus (https://www.sonatype.com/products/repository-oss?topnav=true) instances to great success: for doing everything from mirroring container images that i need from DockerHub (e.g. due to their proposed removal policies for old images and already adopted rate limits), to mirroring Maven/npm/NuGet/pip/Ruby and other dependencies, so i don't have to connect to things on the Internet whenever i want to do a new build.
That not only improves resiliency against things on the Internet going down (apart from situations where i need something new and it's not yet cached), but also improves performance a lot in practice, when only the company servers need to be hit, or my own personal servers in the data center for my cloud hosted stuff, or my own personal servers in my homelab for my own stuff.
Admittedly, all of that takes a bit of setup, especially if you happen to expose anything to the web in a zero trust fashion (permissible for my own stuff, as long as i'm okay with manually managing CVEs just to probably get hacked in the end anyways, but definitely not something that any corporation with an internal network would want to do), but in my eyes that's still worth the effort, if you value being in control of your own software stack and the ecosystem around it.
It's probably much less worth it, if you don't see that as a benefit and don't want to be the one responsible for whatever project you're working on getting hacked, e.g. if you'd fail to patch out the recent GitLab CVE where exiftools could execute arbitrary code, which is probably the case if you don't have the resources to constantly throw at maintenance, in comparison to companies with 100x - 1000x more resources than you have for that sort of stuff.