I think there should be a manual QA process to test the functionality of what the developer is pushing out.
The issue with code reviews is always that they take so much time for another developer and many devs are super busy so they just have a quick review of the PR and approve or feel they have to add some comments. Context switching between what the dev is already doing and having to come to the PR to review properly means they should switch to that Git branch, pull down the code, test it all and check for logical bugs that a static code review won't pick up.
For juniors, code reviews are still useful as you will be able to spot poor quality code, but for seniors, not as much for the reasons above, better off having a QA process to find and logic holes rather than expecting devs to invest so much time in context switching.