For some people no bullet will ever be big enough or powerful enough. As long as theres another bullet out there thats bigger or more powerful than what they've got, thats the one they'll want. They are not particularly concerned about having a good marriage between gun and cartridge. They just want bigger and more powerful. I call em cartridge nymphos.
In my opinion, guns and cartridges must be mated. They are either good combinations or they're not. If you want a really big, powerful bullet, thats ok, but you'll need a really big, heavy gun to shoot it in, if you want to keep the recoil managable. That probably means a gun you're going to have to wear out in the open, which may not be what you want to do. But if you opt instead to go with a lightweight concealable pistol that shoots a great big powerful cartridge, what you get is muzzle blast and recoil that is probably going to make you flinch badly - meaning you may miss on your first shot - and the recoil may be so bad that it slows you down to a crawl trying to getting the gun back in position for follow up shots. I don't like that scenario.
What I want is a bullet that can power its way through to the vitals, through flesh and bone and clothing and some minor obstacles, and I want a handgun that can deliver that bullet on target and be ready to deliver another one on target as fast as I can pull the trigger. A genuine military surplus Makarov pistol firing 9x18 mm Makarov cartridges can do that to my satisfaction. I imagine any of the Brand X guns that have been chambered for the 9x18 mm Makarov cartridge can do it too; however, I'm not sure that all of the Brand X pistols that have appropriated the 9x18 mm Makarov cartridge are as reliable or as accurate as the genuine Makarov pistol is; or are as esthetically pleasing either, for that matter. But I wish them all success because the more handguns that are out there that fire that 9x18mm Makarov cartridge, the more ammo makers will start making cartridges for the caliber, and the more they will experiment to develop a variety of bullet types for that caliber.