Where's the impossible boss?
Stat scaling doesn't mean that your lvl of X is matched by their lvl of X, good stat scaling would be your X+Y to keep you underleveled no matter how much you grind.Anyway, my point isn't that Pokemon is or ever was "hard" without level scaling, it's more that adding level scaling would level (heh) every possible curve in difficulty and leave you in fights where you pretty much only ever press Attack.