Of all the Google dev tools, I miss Critique the most. GitHub is terrible at giving enough context to efficiently review a PR on a second or third pass.
I think coupling commits with review progress was a mistake.
I think coupling commits with review progress was a mistake.
However I think the biggest issue with the landscape for code review tools is that 99% of developers use the default system that ships with their VCS. So on most teams, that's GitHub. People should be actively choosing their code review tools just like they choose their VCS, IDE, CI/CD platform, Issue Trackers, etc. It's one of many tools that makes up your SDLC "Stack".
As long as CodeApprove and Reviewable remain niche they've got nothing to worry about.
It supports some cool things Critique doesn't/didn't, such as reviewing multi-commit branches (also across history-rewriting force-push cleanups), and indicating exactly the nature of your comment (just FYI, or you want this to be changed before you'll give your approval).
(I was an intern in the initial making of Critique, and subsequently got interested in finding an out-of-Google alternative. I contributed a bit to other review tools such as ReviewBoard, and actively used Gerrit, Crucible, Phabricator, and GitLab reviews.)
When looking for a Critique alternative for my startup, reviewable.io had just appeared and ticked all the boxes, and we use it successfully for many years. The drawbacks are that it's GitHub-only and isn't free software.