The idea that AI will make development faster because it eliminates the boring stuff seems quite bold because until we have AGI, someone still needs to verify the output, and code review tends to be even more tedious than writing boilerplate unless you're speed-reading through reviews.
And I suspect the act of writing it yourself imparts some lower level knowledge you don't get by skimming the output of an AI.
[1] https://www.joelonsoftware.com/2000/05/26/reading-code-is-li...
These all sound like your projected assumptions. No, it generally does not take longer to review sizable code changes than it does to write it. This is further alleviated if the code passes tests, either existing or new ones created by the ai.
This has never once been my experience. Its definitely less fun but it takes way less time.