My exact thought. I absolutely love 'relative line numbering' as it lets me use different VIM commands without having to do math. And as I can go to any line number by typing ':<line number>' [generally reported by debugger or other means], I don't really care about actual line numbers anymore.

I've found it occasionally useful when pairing, i.e. "no no, I mean the call on line 23, not 28".

well when you moving around code you want to be in normal mode. so lets say you cursor is at the top of the function which would be 0 (with relative numbering) you could simply look down and see how many lines you need to delete. so for example lets say 5, then you could simply do 5dd or 5yy, without having to count all to see how many lines which can get annoying.

while in insert mode you would simply want to see what line you are one and for collaboration with others. In cases where you might want jump to a line like :15.

There is also a NumberToggle function if you ever need to switch on the go.