I understand some might change what tool they need on the job. A hammer vs a ratchet vs a cake knife, for instance. Hammers don't cut cakes well.
Handguns, however, are barrels with a bullet. The "tool" is the bullet. Changing the barrel means having different ways to activate the bullet, and under stress I don't see changing how to activate it as a positive. Muscle memory and attempting different activation methods seem to be in conflict under pressure.
An extreme might be carrying a .44 Mag in a vertical shoulder holster one day, and a pocket .22 the next. Since we cannot foresee which is the best bullet to use for the situation that may become reality, what purpose is served by choosing a "tool" that could very well be the worst least choice?
We would be better off assessing our overall risk, then choosing the bullet which does the overall job, and evaluating the barrel carrier's qualities for daily protection as a launching device for any situation. Getting specific with one threat means losing some ability to address others. We may think we need the fastest transportation to get to work, but driving a Lambo in bumper to bumper traffic may not be the best answer. A Yugo will do it. Hauling the soccer team after work, a van. Picking up 20 bags of cement at the lumberyard, a half ton truck. What vehicle do you pick for ALL of that? It won't be as fast, or have that one extra bench seat, or have as good mileage, and lumber might stick out the tailgate, but the best answer isn't all four. Not even.
Having all four gehicles is moving beyond simple daily transportation and into something else. It's certainly not proficiency with every one of them, with guns it would take a training regimen 4X more expensive and time consuming. What really results is bare familiarity with any one of them and a degradation of skill, plus introduces hesitancy about which gun you have and how it's going to apply to this specific tactical situation. It's claimed to not be a problem by some, I'm thinking I would look pretty silly patting myself down trying to remember which gun and where it's holstered. Bad enough with winter vs summer carry - which I don't Same gun same holster no matter what works better as there is no options menu to sort thru - same gun same holster every time. Less options means less errors and tactical mistakes.
"Well it must suck being you" is a common refrain and one more based on masculinity comparison, I'm not elevating my cartrdge expense, holster selections, and which set of operating controls I need to remember this day. Rotations become a negative - the expensive watch forums are full of "I had to wind my watch and set it again this morning!" first world problems, the opposite is combat where you only have the one and you sleep with it loaded. Nobody in combat gets to choose if they want the M4, SAW, an M17, or operate the turret gun. You get the one for your job, and saying Oh but I'm an operator I get to choose anyway is only justified when you actually do 4X the training and are shooting 10k of ammo yearly. You also work with other teammates and you understand that the limited number of operators who do this are reduced by one, permanently, every year due to a fatal error in training that much.
Most of us have limited resources and time - and I see threads on "what gun from my extensive collection do I carry today?" as more social status garnering than actual tactical proficiency. Have I got more than one, sure. Of late for every one I acquire I see two being redundant and they need to go. Too many differences and too many calibers to justify them. I literally cannot carry them all at the same time, why then even pretend some are necessary?
I understand having a fork, knife, and spoon makes eating easier, so a knife, a handgun, and a rifle should cover most of the bases. It's all our forefathers had for the most part, same as having a hoe, a shovel and a plow. Not dozens. Just because we can have more doesn't mean we should.
First world problem. Kep that in mind.