I review my own PRs regularly. It’s how I talk through all my changes with meaningful inline comment threads. I prefer the behaviour you’re commenting about because I want to do those things in a “review” rather than pollute inboxes with one-off comments.

I think the main issue is that everyone has their happy paths through review, but those aren’t everyone’s happy paths. It’s why I like that having a variety of tools is possible. GitHub likely has to bias towards the beige middle ground that suits everyone well enough.