If I felt like peeing money away, or hit the powerball, I’d get into one.
I have .30 cal cans, I have zero rifles larger than .30 cal. Buying a .338 that is functionally useless without a suppressor (that I wouldn’t want to buy for this *one* application) would be a silly move when my 300blk SBR does 90% of what the 338 ARC does.
What stuff really needs to be shot with subs? Not a whole lot unless you’re culling animals as a job and want as many kills as possible per night, or something. In that application I could see springing for the bigger, heavier subs.
The stuff I am shooting with subs are the porcupines and skunks messing with my dog in the middle of the night or the raccoon or coyote trying to get into the chicken coop. I only use subs at night so my neighbor that’s 300 yards away doesn’t show up with a shovel at 3 AM thinking someone was siphoning diesel out of my truck (I keed I keed). That aside I would use supers anyways.
For my application, popping nuisance critters and not disturbing the peace in the neighborhood (logging road) in the middle of the night, the 300BLK does absolutely everything I need it to. Plus (and not like the 338 ARC wouldnt perform as well with similar projectiles) the 300 puts a whooping on deer with the 110 TAC-TX and 110 VMAX.
The above, as well as the fact that you can find 223 brass anywhere and make 300blk brass with a saw and a sizing die seals the deal for me. Not that the 338 wouldn’t be a super effective and fun cartridge for the right person.