I may be overly pessimistic about wear and tear on the '73s; I have seen a bunch of loose ones over time, though their histories were (mostly) mysteries. Many may very well have been the victim of being cycled too fast, too many times rather than digesting too many hot loads.
The irony is that the original 1873 Winchester chamberings were bottleneck/tapered rounds, but as you point out, the 1873 "elevator" lets them feed straight in and doesn't really need the taper that seems to help with the 1892 Winchesters and 1894 Marlins. I agree that bullet shape helps to a degree, though I have had pretty good luck with anything that wasn't simply way too long to work. I had a "pet" 1894C that I probably should not have gifted - it was pawned by the recipient during a case of the shorts - that I fussed over until it would pretty reliably feed everything from empty cases to LSWCs cast from some (now collectible) old molds. I still consider getting a .357 Magnum levergun to run trouble-free with a lot of loads to be a bit more of a victory than I do a .44 Magmum.