I'm bias toward the 30-30 myself. The first large bore rifle I was given was a 1928 Savage 99 in 30-30 when I turned 13. That does not make me take a rifle of inappropriate caliber into the field for Elk. There are too many better and larger calibers for that. If you have taken all your Elk with one shot kills with a 30-30, you must be quite the stalker.
I am "quite the stalker," actually. That's probably because my first gun was a lever action .30-30 and I learned fairly quickly to work within its "limitations" instead of fretting over them. It turned out that the .30-30 really wasn't all that limiting to me, in spite of the fact that I have spent most of my hunting career on ground that was relatively "wide open" country, with some of that being in terrain where trees were a rare sight. Starting off the .30-30 forced me to exercise some discipline before pulling the trigger, and to conduct my hunting in a manner that would put my intendend quarry within range of my rifle, even when there wasn't a tree in sight for miles.
I don't mean to be a stickler for accuracy, but I didn't take all of the elk I've killed so far with a .30-30. I've only killed six of them with the round. I've taken another six with the .270 Winchester, and a few more with a .495" patched round ball from my muzzleloading Lyman Great Plains Rifle.
I could have killed all but one of the 14 elk I've taken with a .30-30, though. My hunting game doesn't change much due to the rifle I've got in my hands. Even if I still had my No. 1 in .300 Weatherby, or the No. 1 Tropical in .375 that replaced it, I'd still want to get as close as possible before pulling the trigger. And I still would.
Fourteen elk in a lifetime doesn't make me an expert on the subject, but the novelty of killing one wore off the first time I lined up the sights on one and squeezed the trigger. If I have to pass up shots because my rifle isn't up to the task of taking them, that's okay with me. I'll go find another than I can shoot with the rifle I've got. Or I might even go home as elkless as I was when I arrived in elk country. That's okay, too. I've got plenty of seasons left to shoot another one.
I doubt if they've become even more bulletproof in the here and now than they were in the late 80's and 90's when I was hunting them actively. I didn't need a belted magnum for elk hunting then and I doubt I'll need one going forward.
I could use a good trail horse, though
.... And a trailer to haul it around in..... And maybe a mule or two.....
JP