What do you use instead of PRs? (Honestly, not using PRs and paying for GHE sounds like a... less-than-ideal way to spend your money?)
The PR workflow + Checks are a good "equivalent" (IMO, nicer) experience to pre-commit hooks.
Yes. Because I already have git, which by definition already does 99% of what I need as a user. Issues + remote repo admin + CI/CD are the exceptions.
What do you use instead of PRs?
Direct commit with no branching. IMHO PRs are an arguable misfeature of hosted RCS/VCS to keep people on those platforms. We have a high proportion of non software development projects/users.
Committing directly might work for a small team, but I can't imagine that scales.
I suppose we want fundamentally different things here, and sadly for you, I don't think you're a large enough portion of the audience that GitHub will ever create the tool you need.
Their APIs are open, though -- you can probably make one yourself.
You are the minority.