One 1 hour doing code review is not really stolen from doing feature work really is it? For the vast majority its stolen from playing video games or some other non-work.
That heavily depends on the individual developer and the organization in question.
In general, the most highly skilled developers who are most capable of doing a thorough code review are also the ones who are most likely to be genuinely over capacity as is.
In general, the most highly skilled developers who are most capable of doing a thorough code review are also the ones who are most likely to be genuinely over capacity as is.