I use scroll lock so infrequently that when it got bumped by accident today, I didn't know what was happening and had to ask Google to figure out why my arrow keys didn't work right.
I'm not entirely sure that I've ever turned it on on purpose. Is there a use for it in today's world? Other than for someone who uses keyboard mappings for literally everything so they have some macro of CTRL-ALT-SCRLK-A-B-RtShift that sends their mom flowers on her birthday?