What makes Mahomes so dangerous isn't his speed but how pants on head ridiculously elusive he is, how well he senses pressure in the pocket, his movement within said pocket and his sense for knowing when he needs to bail.Tannehill is faster than Mahomes and probably a better athlete (Tannehill was a WR his first 2 years at A&M.) but of course not the passer and can't even make some of PM's throws. Mac Jones is faster than PM, though Mahomes is the better athlete. RT 4.65, PM 4.8, MJ 4.74 - against stereotype.
A lot of people bag on him for that Super Bowl loss but the offense being discombobulated wasn't on him. I mean it does look bad if you're serpentining 20 yards behind the initial LOS but he really didn't have much choice. Think he ran around for close to 500 yards trying to escape pressure all game. Even then he made several great throws on which his receivers let him down.
If anything that game should have shown people how quickly things can go sideways if your offensive line isn't cohesive. They were down 2 starters and the Bucs were getting immediate pressure from the snap all night.