Clipless holds you to the bike, I have ridden trails so rough that if your not clipped in you will get hurt.
200 yards of exposed roots and 500 yards of baby head lava. If your not connected you cant finish the ride. It is unusual If you ride buff single track with some freeride rock jumps thrown in I could see
wanting to unclip. For me it just slows me down. Really just depend on where your riding. I have seen
buff single track thrown in with car sized rocks you have to negotiate. Maybe not the norm but I dont know were you ride (I would unclip for car sized rocks).