Lawenforcement has video of cops who under attack can not use a decocker lever on a pistol that is larger in size than an extended slide stop on a glock.
The main point is that if you are going to use a pistol for self-defence the small muscle memory groups will fail to get the job done when you need them to work.
Racking the slide is the major muscle group that can be trained to work under stress where the small muscle groups can not be trained.
Your point Is good what if no belt I teach to use anything like, a heel on your shoe, sole of the shoe, bumper, chrome on a car, door frame or an edge of a table. Anything near will save the day.
In addition I teach to carry an off-side knife that can be pulled and opened weak hand (non-gun-hand) if your gun goes down or the bad guy is trying to remore it from your holster. In that case one puts his gun hand on the bad guys had and holds his hand on the gun while pulling the knife and stabbing the bad guy so he does not get the gun and shoot the officer. A lot of this is for open carry persons.
I hope this works if not please let me know.
Your life is all important to me. Dam the bad guy he can just go to 7734!
Good Luck and be safe.