The people saying that Sonic simply isn't as versatile are right. Sonic's world was just never fleshed out the way Mario's was. Sonic's world is full of contradiction, since originally it seemed to be about an animal living in a world of animals and fighting an evil human, then with Adventure they threw all that out the window. From Adventure to Shadow the Hedgehog, it seemed like they were trying to build a world with some sort of continuity, but then just dropped it all from Sonic 2006 onward, and even more so with the Sonic storybook series.
That was one of the problems with Sonic Chronicles. With Mario RPG and Paper Mario, the items you used made sense within the Mario continuity, but then there was Sonic Chronicles: POW Candy, Rock Salt, Clover Juice? wtf?
Monster Hunter: pissing me off since 2010.
