I believe, the biggest reason fot the advent of premiums was, and is mag. rifle velocity. Some want to hunt at longer ranges when needed, hence started the "magum craze" of the 60's. Problems came, because most game was still being shot at rather short yardages. Hence, alot of bullet failures. In turn which brought about the need for complex bullet constuctions.
From what I have seen, most bullet perform (expand) well, down to 1800-2000 fps range ( even the prems.). And from what I have wittnesed, and heard, most conventioal bullet failures occur, when terminal velocities are above 25-2600 fps. ( with maybe too light bullet to begin with)
I don't shoot magnum velocity rounds much ( not at big game). But I still like the assurance that comes with premium bullets. I'm all for penetration, when given the option.