There is a case to be made for not using collars when benching <span style=”text-decoration: underline;”>on your own</span> as you can ditch the weight if need be.
On your own doesn’t apply to a public gym unless there is nobody else there obviously, in which case, use collars, don’t use collars, it doesn’t matter. In a busy gym, nobody is going to stand by and watch you choke to death, whereas if you are pinned and panic you could ditch the weights potentially on to me if I’m loading my bar at that time.