Yeah, I get that. That's why I often ask for developers to document the why, not the what.
// Now increment idx by 1
idx++;
Might become
// Skip over the length byte
idx++;
But indeed there is an argument for not documenting the bleedin' obvious, so long as we allow for the fact that what's obvious to some of the smarter devs on my team may not be so obvious to all the devs, or even to me