This report of the first GitHub Open Source Advisory Board meeting, written up by the author of Fossil, is thought-provoking on the issue of Github's role in open source these days.
I'm personally not a fan of Github and the monoculture it seems to tend towards (with Github being the de facto default destination of open source projects) so I host quite a bit of my code on my own server instead,1 so I tend to agree with many of the points Richard makes in his analysis. Though at the same time Github has its advantages, especially considering that it provides all of its resources for free without any real limits due to being subsidized by its enterprise offerings.
1 Right now I'm using Gitea for this but I feel like it's quite bloated and resource-intensive, especially for a small VPS. The perfect alternative would be to write a solution of my own but that will be quite resource-intensive and something I don't think I could extract a lot of value out of.