[cableshaft]

So you're advocating for pair programming all of the time? As someone who has to do both pair programming and code reviews quite a bit this past year (mentoring some quite junior developers), I find pair programming much more mentally exhausting. Two hours of that and my mind is pretty much spent for the day.

[lmm]

IME PR reviews are generally a half-assed substitute for pair programming. I don't really enjoy doing pair programming, but can't deny the effectiveness.

[aftbit]

I don't read the parent as advocating for pair programming, just that any given part of the code should be understood by at least two people. This is possible to achieve even on a fully asynchronous team.