> I don't personally think that Github makes PR formatting any harder
GitHub deliberately made GitHub-flavored Markdown incompatible with the way that Markdown dictated line breaks should be handled, although this affects more than just pull requests. In general, the way that people "write" Markdown meant to be published for GitHub is unreadable as plain text, even though it's supposed to be roughly as nice to read raw Markdown as it is to read the rendered form.
Many projects' commit logs are also a mess as a result of the way that GitHub pushed their pull-requests-for-everything model on the world. There is no end to the number of projects where every other log entry is a crufty merge commit, and the messages in those projects are generally useless, anyway. Folks shouldn't have to trawl through a disconnected web service to glean the info that should have been included in the commit message but was stuffed into the pull request instead.
> Now, I'm not necessarily super crazy about Github and the like. But for these issues, in my opinion they do a pretty reasonable job.
I have no horse in any Emacs race, but I agree that proper bugtrackers trump mailing lists. It's just a shame that so many people have consolidated around GitHub (and workalikes, like GitLab and Gogs/Gitea), which is poorly implemented. GitHub implements less-than-optimal workflows for its own reasons, and those reasons generally mirror other Valley-based "social" endeavors, where what's most important is growth, user engagement, and the perception of value at the expense of actual productivity and the adoption of addictive dark patterns to drive it all.
Second to the actual mechanics of GitHub is "the GitHub community", which routinely proves to be as much of a liability as an asset.
The fact that Emacs is a free software project and GitHub is not and GitHub is only slightly less of a walled garden than Facebook and that its privacy controls (what little it provides, if you want to even try to argue that it provides any) are worse than what Facebook and Twitter provide...
... are all reasons that make for a very bad suggestion to move to GitHub.