looking more for an administrative CLI for Github, rather than the usual "Github user" experience
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.