I've shot many more small game/varmint/vermin with something on the order of a 32-20 than I've ever shot with a 22 LR or shotgun, and not because I've never used a 22 or shotgun. Each is wonderful and covers a LOT of applications, but I've found the centerfire 30s and 35s to be more versatile by a long cry. My shotgun hangs idle, waiting for bipedal intrusions and I don't even own a 22 any more.
The 35s, particularly the 357 Mag CAN be employed well outside of its originally intended purpose, from squirrel to deer and back to personal defense AND has the benefit of compatibility with a "reasonable" handgun. I say "reasonable," because my best friend would argue that his 458 Lott Encore pistol is compatible with an African hunting rifle.
I ruled out the 300 BLK as my own ONE 30 caliber rifle, in deference to the 30/30, which also beat the 7.62x39 - for ME. The 300 BLK, as well as the 7.62x39 both provide a lot of latitude in application and DO each have their shortcomings, but so does the 30/30, the 357, 22 LR and shotgun. I definitely wouldn't write off the BLK as useless, at least no sooner than I would the 32-20, but one picks and chooses one's own compromises for one's own situation, likes, dislikes, etc.
Once I got serious about the probability v. possibility of certain situations, I was able to determine my own perfect combination of compromises in cartridges and arms.
It all IS nutritious fodder for intelligent discussion regardless. Keeps the brain busy working on constructive and productive things.
To split a hair or two here, I'm not an AR guy, but am a big fan of the CZ 527 and what fits into an AR usually fits into a 527. Can't put a 30/30 in a 527. My "main" long-arms in my battery are neither, rather Contender Carbines, so MY long-arm of choice would be no shorter or lighter if it were a 300 BLK, so it's a 30/30. No sense hobbling myself (even if just a little) with a smaller case when the larger case does so well with small charges AND offers a bit more punch on the top end/heavier bullets. AND, I just love that long neck and big rim, subjective though those points might seem.