I’m really curious about the teams that need this. To me it seems like a non issue, and a symptom of disorganization.
Hope you don’t take this the wrong way, kudos to you, I can see from testimonials that it helped a lot of people.
Pretty much every team I've worked as an IC or manager has had this problem. By "problem", I mean that pull requests take more time and more cycles of communication to review and merge than is ideal, which means things get shipped slower. I think the problem is actually pretty universal.
It depends on the team size and scope. A team of many individuals working on parallel streams need some discipline to manage, especially across many repos, and things like this help.
However it does seems like a github/gitlab/whatever feature away from irrelevance.