The Sonic series should never have given Tails, Knuckles, Rouge, etc. their flying, gliding, and climbing abilities in the first place. Because of it, even Sonic 3 & Knuckles had to struggle with trying to balance "speedy" Sonic while providing exploration opportunities for the other characters, causing it to have slower-paced level design than Sonic 2. And the 3D games were forced to give the non-Sonic/Shadow characters those unfocused and overly divergent gameplay styles during the Adventure era, and modern Sonic games can't even incorporate Tails, Knuckles, etc. at all because the stages in those games are overly designed for Sonic's abilities and not for flying, gliding, and climbing.
But it's not too late to break that tradition. Tails and Knuckles' gameplay can still focus on other things like Tails's gadgets or Knuckles's strength. Or at least take the Kirby Forgotten Land approach and give them severely nerfed flight and gliding.