I just think at times people try to push the boundaries of a projectile/cartridge combination when the answer can be as easy as just going up in cartridge & calibre.
Just my view!!
Sometimes, but not always. Varied caliber bullets have differing BC's, and sometimes the lesser caliber bullet may have a higher BC and can be driven faster with a smaller case capacity. When simply shooting LR targets, steel gongs or smaller game/varmints, a heavier, larger caliber bullet isn't always needed nor desired. 1,000yd BR comes to mind.
Added: Other considerations for active LR shooters are component costs, heavier recoil, faster barrel erosion/costs, possible noise factor, etc. I've trained youth and inexperienced LR shooters, and practice myself, with a fast twist, long throated 26" 223 with 75-80gr bullets, and the cost savings of components compared to my larger hunting calibers allows for 2-3 times as many shots per cartridge and the barrels last 5,000+ rounds before setting back.
So there can be many advantages of using smaller and/or faster calibers for things that do not require a heavier caliber. And besides, its our hobby and fun to experiment with different things.
Here is a 1,000 yd 223 75gr loaded with AA2520 that leaves a 26" barrel at 2970fps, so its BC, flight performance and velocity are similar to many larger, more expensive and harder kicking calibers. Thus allowing for more training, more shooting fun and less end-of-the-day head/body aches.