I like line numbers because when I'm editing code in a remote meeting, I or someone else can refer to lines by number. The current line is not the only one that matters. I use relative line numbers because I like doing e.g. 9k or whatever. Others on a remote call often refer to other parts of the code with "9 up" or "9 down" (since "9k" and "9j" sound too alike in a noisy call).
It makes it easy to jump to other lines on your screen, e.g. maybe you want to split out half the code from a loop to another function. You can't use di{ to delete everything in the {} because you only want half of it, but if you can see that the loop contents end on line 98 you can go d98G