When you hunt dangerous game like a 400+ pound black bear or a 1000 pound male moose, do you use a 30-30 or a 30-06. You go with a round that has more energy and with a greater bullet weight that will hopefully take care of the issue in short order. I hunted with a 180gr 300 Winchester mag. for all dangerous critters.

Getting to the original question of what use is a 45acp. Except for the 180gr 357 mag which has a mean recoil and a longer recovery for a second shot,the 45acp in 185gr+p has equal or more energy and makes a bigger hole which with or without expansion will create a larger and more forceful wound cavity than any other caliber below it along with breaking bones when hit etc. and has a higher round count than most revolvers,it’s also good for going through car doors, windshields etc..
The 45 also has a faster recovery time for that second shot.
Everyone must remember that the idea behind a military round is to wound a solder so it will take not only the one shot out of the fight but also one or two more comrades to take that solder to safety. That is why hollow point ammo is not allowed in combat.
So I would consider someone that was trying to take my life a dangerous critter and I believe the 45acp is the round that would do the job better than any other! JMO
A local Police Department used 45acp 200gr Speer Gold Dot reg. Vel in Glock 21’s for many years.

Be SAFE and Shoot often!