Over the years I have seen what a lot of people do and heard a lot about why they think their ways are the best.
I've worked with cops carrying revolvers with cylinders loaded with different combinations of ammunition (2 .38Spl. JHP's, 2 .357 JHP's, 2 .357 AP's, or some other combination), anticipating a combat situation unfolding in certain ways. A Ouija board may have been used to determine that.
I've known cops who carried 2" Chief Specials while working plainclothes assignments, but went to their range qualifications with 6" K-38's or Colt Pythons.
I've known LOTS of cops who never fired anything but .38Spl target loads for training or qualifications, but went out on the street every day loaded up with .357 SuperVel 110-grain JHP's (WAY DIFFERENT point of impact in relation to point of aim).
As a supervisor, and later as a chief, I've inspected cops guns and gear and commented on the age and experience of the lint and spider webs, not to mention the accumulated crud and gunk that can result from NEVER having received a proper cleaning, and way too much oil slopped into the works.
I've known lots of guys (cops & civilians) who change guns and carry gear the way other people change socks and underwear. I've heard lots of talk about "carry rotation".
I've heard just about every possible argument in favor of, or strongly against, each caliber or bullet type and every conceivable handgun (revolver, semi-auto), etc, etc, etc.
Personally, if I really believed that I would be involved in armed combat on a particular day I wouldn't leave the house without a shotgun, rifle, sidearm, back-up gun, all the ammo I could carry, and two or three armed friends.
I carry the same sidearm every day, in the same holster, on the same belt, at the same position, loaded with the same ammunition. I shoot about once per month with the same handgun, using up the ammunition I've been carrying and replacing it with new ammo of the same type. I clean the pistol thoroughly after firing, lubricate it sparingly, and wipe it down every day when I take it out of the holster for the night.
At home I keep a loaded 12-ga. Remington 870, just like those I've been using for over 40 years. On road trips I usually put a loaded M1 Carbine behind the seat of my truck, or in the trunk of the car, another piece that I have over 40 years of experience with.
I have other firearms, and I enjoy them all. I hunt small game with a .22 revolver, .38Spl revolver, and an original antique percussion rifle of about 1860 vintage. I hunt larger game with .357 revolver, .44 magnum revolver, and centerfire rifles from .25 to .45 caliber (some over 100 years old that require me to cast bullets and load my own ammo because it just hasn't been made during my lifetime).
But for personal defense I use the same equipment every day and train with the same equipment every time. If the worst case scenario develops I don't want to have to stop and think about which gun I'm carrying, where am I carrying it, is there a safety to disengage or not, which ammunition it is loaded with, what is the POI compared to the POA, or any of the other complications that might cause me to lose a fraction of a second in response to the threat.
But that's just me. Recreational shooting is one thing. Self defense is something else. Lots of other people have different opinions about what is best for them.