The reason I don't spend the majority of my time in code review is that when I'm reviewing my teammates' code I trust that the code has already been substantially verified already by that teammate in the process of writing it and testing it. Like 90% verified already. I see code review as just one small stage in the verification process, not the whole of it.
The way I approach it, it's really more about checking for failures, rather than verifying success. Like a smoke test. I scan over the code and if anything stands out to me as wrong, I point it out. I don't expect to catch everything that's wrong, and indeed I don't (as demonstrated by the fact that other members of the team will review the code and find issues I didn't notice). When the code has failed review, that means there's definitely an issue, but when the code has passed review, my confidence that there are no issues is still basically the same as it was before, only a little bit higher. Maybe I'm doing it wrong, I don't know.
If I had to fully verify that the code was correct when reviewing, applying the same level of scrutiny that I apply to my own code when I'm writing, I feel like I'd spend much longer on it---a similar time to what I'd spend writing on it.
Now with LLM coding, I guess opinions will differ as to how far one needs to fully verify LLM-generated code. If you see LLMs as stochastic parrots without any "real" intelligence, you'll probably have no trust in them and you'll see the code generated by the LLM as being 0% verified, and so as the user of the LLM you then have to do a "review" which is really going from 0% to 100%, not 90% to 100% and so is a much more challenging task. On the other hand, if you see LLMs as genuine intelligences you'd expect that LLMs are verifying the code to some extent as they write it, since after all it's pretty dumb to write a bunch of code for somebody without checking that it works. So in that case, you might see the LLM-generated code as 90% verified already, just as if it was generated by a trusted teammate, and then you can just do your normal review process.