Kind of seems like two separate topics being discussed. One is revolvers, and the other is pipsqueak cartridges.
My opinion is that folks have tended toward dismissing revolvers for decades. That makes some sense from a military and police standpoint, but I don't buy most of the arguments against revolvers for armed citizens. These days especially, the high-speed/low-drag kids act as if revolvers are completely useless in a fight - as though you just suggested running Daytona with the family sedan - and aren't interested in even discussing it. No skin off my nose, except for the fact that they sometimes convince people who actually would be served better by a DA revolver than any other gun.
Now, the pipsqueak cartridges? They've largely been left behind because they simply don't work very well. Especially when loaded with FMJ for reliability, things like the .25 just can't be expected to have any real effect in a gunfight. Yes, just "having a gun" works in many instances, and yes, there are instances of fights being won with such things, but honestly, if you wouldn't hunt deer with it, why would you trust your life on it?
Maybe think in terms of this...
Sometimes winning is just surviving. We are talking defensive pistols now so even just a 25 can be benefitial... optimal... no. Optimal would be a shotgun or rifle but thats kind of hard to tote around. A small pocket auto 1. Lets the aggressor know your willing to defend yourself and 2. Can help create an opportunity for you to get away. Put yourself in the mind of a criminal... not necessarily a killer or assasin. Your average criminal wants an easy target that doesnt or cant fight back. A small DEFENSIVE pistol can provide that edge. Nobody likes bullets flying in there direction... not even predators...not even 25acp, black powder etc. etc.
Again... winning in defense is just surviving. Now if we start talking OFFENSIVE firearms... thats a whole different story. I wouldnt want to be stuck with just a 25 or 32 in Grizzly bear country. Luckily humans are not giant monsters.
Hunting deer is an offensive action. CCW carrying is a defensive action. Seems like a LOT of people these days want to make it out to be a competition or gunslinger/gunfighter type scenario. That kind of mindset is kinda shakey IMO in civilian non LE CCW roles.
Of course we live in times of crazy scenarios with mass shooters etc. so its nice to have more bases covered of course. The likelyhood of tht kind of event is a lot less than a mugging or typical aussault. Its just up to the individual to decide on what they are comfortable with accepting in terms of likely threat. Overwhelming majority of people just want to be left alone not play hero with their CCW. Im certainly not interested in staying around if there are other options. In the event of a mass shooter not only is the shooter a threat but you also have to consider all the other CCW holders. Friendly/mistaken fire can be an issue. Bullets coming from all directions with scared people yanking on the trigger, point shooting etc. etc..........No thank you... not for me. Im not interested in becoming a human bullet trap for anyone... including CCW holders.
One other thing I would say is if someone has no mobility (overweight, disabled etc. etc.)... best to have a little more firepower. If you cannot physically run or flee a scene you have essentially made yourself a soft target for a predator. I tend to carry a little more firepower when I am out with my kids/family because fleeing the scene rapidly introduces complications. If I am out alone a good pair of running shoes is likely more important than the CCW (Im pretty quick). A stray dog attack is a much more likely event than a human attack.. therefore I carry Halt Dog Mace more than I do a firearm. Im always suprised more people dont. Kinda hard to out run a dog.