I've got no doubt that a 9mm carbine and even a .22WMR rifle are "enough" for many deer, if the hunter does his part. The .22 mag has probably 300-350 ft/lbs, and the 9mm should have 500-600, as it has 400+ out of a pistol.
I hunt with one guy who still uses a .32-20 lever gun, and uses it very successfully. This thread got me curious, so I looked it up. The .32-20's only got 325 ft/lbs at the muzzle, which puts it in the same range as the .22 magnum. Admittedly, it's shooting a heavier bullet, and energy isn't the only relevant factor, but it's "a" relevant factor. The .22 magnum at the muzzle has the same energy as the .32-20 at the muzzle, and the same at 50 yards as the .32-20 has at 100 yards; so it's "in the neighborhood". Not ideal, granted, but usable.
When I run across the typical power-mad hunter that just has to have a 7 mag for whitetail, I like to remind them that for a lot of years, north americans were using the .32-20, .25-20, .44 rimfire, etc, as their normal "everyday" guns, for hunting and defense both. So while those guns may not be 'current', they're demonstrably 'capable'.
Regarding the "monster revolver", I just like mine. It gives me pleasure. No reason I "have" to have it, any more than there's a reason I "have" to have extra rifle magazines, more than one watch, or satellite tv. I just choose to.