I think this is an instance of a fairly common pattern.<p>Not all good ideas/implementations arise from the FOSS community. And sometimes, there's something that's so clearly better than the alternatives, that it becomes widely used despite being commercial.<p>Previous examples I'd cite are Solaris, Purify, vTune, BitKeeper, Sublime Text, macOS, etc.<p>Generally, some time passes until it becomes clear what it is exactly that is key to the experience, and those things are then either replicated or extended in FOSS, and people then move away.<p>eg. Linux has replaced Solaris, Git replaced BitKeeper, valgrind replaced Purify, etc.<p>There's also a spectrum of people in the community: some who are willing to use commercial products pragmatically, and others who aren't on a more purist stance. GitHub clearly has very broad adoption, but since the Microsoft acquisition especially, GitHub and SourceHut appear to be attracting more patronage.