Handgun calibers aside from 357 magnum and up, really just don't work. People actually think having to shoot a guy 10 times with a 9mm is super effective, when a .22 gets it done equally as fast. Equally as fast, because handgun bullets suck. You only carry a pistol because you can't conceal an 18" ar-15 with a full stock and optics.
They just try to fit as many of a bullet into the smallest gun they can that people are willing to shoot. Slow bullets are garbage and you just need to aim and flick your finger as fast as possible until your gun is empty, reload and repeat. 380 fits into smaller guns and has less recoil for a smaller gun. 30 super let's you fit a couple more bullets in what is likely to be a tiny carry gun. 9mm is super common and most affordable. 45 is cool and 45 ball ammo is actually rather effective, so you don't have to be a fancy pants with your ammo. 44 magnum or better will completely wreck any person you hit and probably wreck the little kid standing behind them, too. Older guns were weaker and so were their cartridges. How many .38, .36, .25, .32 cartridges are there that were each barely stronger than the last one, but could be fired in the fancy new space gun? 32 short, long, h&R, 327 magnum all just longer and more powerful versions of themselves. Different countries also made their own calibers for their own guns. Mexicans can't own "military calibers" so their 1911s are all in ,38 super. We had the 45 colt or acp, the Brits had 455 Webley. .25 and .32 are traditionally British calibers. America had at least half a dozen 36-38 police calibers and the 38 special was called a special because we didn't call anything a magnum yet. The most powerful handgun on earth was the .45 colt walker, which is as big and heavy as an X frame. It's a percussion revolver. It held that title until the 357 magnum came out in 1935, which held the title until 44 special was worked up, then made into the 44 magnum in 1955. For like 100 years, a cap and ball gun was the strongest until 357 came in. Those calibers were all on 3-4 pound guns!
TLDR;
Find THE gun that feels good, that you WILL carry, and that you shoot well. If the gun works and it works for you, that's all that matters. Shooting your target is pretty basic for a species that is the best at throwing anything with unimaginable accuracy for any other species to ever exist. Real men only carry magnum revolvers, anyway.
They just try to fit as many of a bullet into the smallest gun they can that people are willing to shoot. Slow bullets are garbage and you just need to aim and flick your finger as fast as possible until your gun is empty, reload and repeat. 380 fits into smaller guns and has less recoil for a smaller gun. 30 super let's you fit a couple more bullets in what is likely to be a tiny carry gun. 9mm is super common and most affordable. 45 is cool and 45 ball ammo is actually rather effective, so you don't have to be a fancy pants with your ammo. 44 magnum or better will completely wreck any person you hit and probably wreck the little kid standing behind them, too. Older guns were weaker and so were their cartridges. How many .38, .36, .25, .32 cartridges are there that were each barely stronger than the last one, but could be fired in the fancy new space gun? 32 short, long, h&R, 327 magnum all just longer and more powerful versions of themselves. Different countries also made their own calibers for their own guns. Mexicans can't own "military calibers" so their 1911s are all in ,38 super. We had the 45 colt or acp, the Brits had 455 Webley. .25 and .32 are traditionally British calibers. America had at least half a dozen 36-38 police calibers and the 38 special was called a special because we didn't call anything a magnum yet. The most powerful handgun on earth was the .45 colt walker, which is as big and heavy as an X frame. It's a percussion revolver. It held that title until the 357 magnum came out in 1935, which held the title until 44 special was worked up, then made into the 44 magnum in 1955. For like 100 years, a cap and ball gun was the strongest until 357 came in. Those calibers were all on 3-4 pound guns!
TLDR;
Find THE gun that feels good, that you WILL carry, and that you shoot well. If the gun works and it works for you, that's all that matters. Shooting your target is pretty basic for a species that is the best at throwing anything with unimaginable accuracy for any other species to ever exist. Real men only carry magnum revolvers, anyway.