Sharing knowledge, improving code quality, readability and comprehensability, reviewing test efficacy and coverage, validating business requirements and functionality, highlight missing features or edge cases, etc. AI can fulfill this role, but it does so in addition to other automated tools like linters and whatnot; it isn't as of yet a replacement for a human, only an addition.

The better your code is before submitting it for review, the smoother it'll go though. So if it's safe and allowed, by all means, have copilot have a look at your code first. But don't trust that it catches everything.

What was the purpose of ‘very basic’? The semantic value of that diminishes the concept of a code review. Why?

Power play for devs who don't get to do that very much otherwise. Only 80% /s.