it's far from settled that the 68k in the Genesis was more powerful than the 65816 in the SNES. Most instructions on the 68816 use 1/3 of the cycles per instruction compared to the 68k. Sega had their marketing of "blast processing" because Sonic was a "fast game" we all know what was pure marketing. Similarly fast games, meaning games that displayed the same features as Sonic, came out on SNES, Uniracers would be one such example.

I think it would be pretty hard to find a Genesis game that would unequivocally demonstrate the 68k in the Genesis was a win over the 65816 in the SNES.