Wow... If this has been your experience then you've had rotten luck. I've never experienced this in 25 years developing professionally.
On a typical code review, a reviewer takes about 10-15 minutes tops to review the code in a PR. 75% of the time the code just gets approved. Otherwise it's usually a few minor points that are 2 minute fixes, and rarely it becomes more involved because the person was unaware of something important (so a 20-30 minute fix, or perhaps a meeting to discuss the issue and come to a concensus if nobody's really sure how to deal with it).
PR code chunks are kept small so that things are easy to review, and easy to switch back to if there's a problem. Generally there's 0-1 cycles per review. If we're working on something big, we make an integration branch for that feature and then merge the changes in multiple small PRs again, so that only the integration branch itself needs to be kept up to date with mainline. Blockages due to unmerged code are unheard of (at least I've never experienced it).
I do on average 3-4 code reviews per day, and this has been my experience for my whole career (aside from two places that did pair programming instead) spanning many companies from startups to multinationals.
On a typical code review, a reviewer takes about 10-15 minutes tops to review the code in a PR. 75% of the time the code just gets approved. Otherwise it's usually a few minor points that are 2 minute fixes, and rarely it becomes more involved because the person was unaware of something important (so a 20-30 minute fix, or perhaps a meeting to discuss the issue and come to a concensus if nobody's really sure how to deal with it).
PR code chunks are kept small so that things are easy to review, and easy to switch back to if there's a problem. Generally there's 0-1 cycles per review. If we're working on something big, we make an integration branch for that feature and then merge the changes in multiple small PRs again, so that only the integration branch itself needs to be kept up to date with mainline. Blockages due to unmerged code are unheard of (at least I've never experienced it).
I do on average 3-4 code reviews per day, and this has been my experience for my whole career (aside from two places that did pair programming instead) spanning many companies from startups to multinationals.