Code review is rarely done live. It's usually asynchronous, giving the reviewer plenty of time to read, digest, and give considered feedback on the changes.
Perhaps a spicy patch would involve some kind of meeting. Or maybe in a mentor/mentee situation where you'd want high-bandwidth communication.
My first job did IRL code reviews with at least two senior devs in the loop. It was both devastating and extremely helpful.
Doing only IRL code reviews would certainly improve quality in some projects :)
It's probably also fairly expensive to do.