No, my argument is valid.
Untold numbers of deer are shot with .30-30 lever action rifles, with 150 grain bullets traveling around 2400fps at the muzzle. You can also shoot a .30-06 with a 150gr bullet at 2900fps.
How far are most deer shot when shot with a .30-30? I'd wager on the low side of 75 yards, and that's generous. At 75 yards, the .30-30 should have around 2085fps.
How about most shots with the .30-06? Let's say 150 yards. With the exact same bullet(not something very likely, but possible if you handload), velocity at 150yards is about 2200fps.
So, there would be a difference of 115fps between those two instances. How many people are actually hunting with cartridges whose impact velocities are anywhere near their starting velocities? It's the golden rule of hunting, know the capabilities of the shooter, the weapon, and the cartridge as loaded. That's what matters when it comes to stuff like this. Would you take a .30-30 lever action out hunting in the wide open of Kansas? Probably not. Would you hunt in thick timber with a .30-06 if you knew your shots were going to be under 100yards?(I know people who shoot deer with .300 Mags at under 100yards-silly) If it's your only option, it's more than likely going to happen. But, I've seen deer hit with the .300 Mag at 50 yards travel 3 times further than a deer hit at 50 yards with a 7.62x39. The reason is bullet construction. There's so much more to shooting than just velocity. Of course, speed sells so whatever is faster must be better.
But you already knew all that, didn't you?