Well, Sonic has a better arch nemesis, better backstory, stronger abilities, and can run faster than sound and sometimes faster than light. If Sonic fought Mario, Sonic could just turn into Super Sonic, travel to the edge of the galaxy, supercharge a spindash, and zip all the way back to Mario, because of the momentum and velocity that attack alone would destroy Mario and create a giant crater on the planet or straight up destroy the planet. And if Sonic wanted to, he could turn into Hyper Sonic and erase Mario with a thought. But, that's my opinion.