GitHub issues (well, PR comments specifically) is possibly the clearest example of developers not knowing how their users use the product. There are only 3 important user stories that matter for this workflow and none of them are done well:

- I want to review surrounding code and get context for a line level change. Can't do it without clicking multiple expanders and even that has a limit of 2 or 3. I also can't comment on surrounding unchanged code which is sometimes extremely relevant, like "copy this pattern"

- I want to see all the unaddressed issues. Ones that are not marked as resolved and not replied to, however you slice it, the issue filters simply don't work

- I don't want the PR author to be able to resolve issues without me getting indicated to verify them. The workaround is them commenting "fixed" on every issue. Make the button say "mark as resolved" and "verify resolved"

- Bonus: if you've got more than 40 comments on a PR, good luck finding some random subset of them. They're just unavailable and the UI unapologetically says "eh can't do it". Yeah small PRs but it happens.

Popup or inline i don't really care, the baseline workflow is completely uninformed.