> a pioneering (but no longer new) PR system
having used gerrit 10 years ago there's nothing about github's PRs that I like more, today.
> code navigation simply in a web browser
this is nice indeed, true.
> You write code, and almost everything works effortlessly.
if only. GHA are a hot mess because somehow we've landed in a local minimum of pretend-YAML-but-actually-shell-js-jinja-python and they have a smaller or bigger outage every other week, for years now.
> why developers like it so much
most everything else is much worse in at least one area and the most important thing it's what everyone uses. no one got fired for using github.
> having used gerrit 10 years ago there's nothing about github's PRs that I like more, today.
I love patch stack review systems. I understand why they're not more popular, they can be a bit harder to understand and more work to craft, but it's just a wonderful experience once you get them. Making my reviews work in phabricator made my patchsets in general so much better, and making my patchsets better have improved my communication skills.
The main thing I like about Github's PRs is that it's a system I'm already familiar with and have a login/account for. It's tedious going to contribute to a project to find I have to sign up for and learn another system.
I've used Gerrit years ago, so wasn't totally unfamiliar, but it was still awkward to use when Go were using it for PRs. Notably that project ended up giving up on it because of the friction for users - and they were probably one of the most likely cases to stick to their guns and use something unusual.