Hardly. There's a ton of untapped potential in Sonic, as shown through his good games, or at the very least, the good parts of his games. And despite the clearly bad games, his **** still sells.
What needs to be put down for good is Sega's management, or at the very least the management at Sonic Team. They're schizophrenic and unconfident with their ideas, relying on new gimmicks instead of actually fleshing out Sonic's gameplay in a natural way, a la Mario's games like Galaxy, Odyssey, 3D World, etc.
A perfect example is Unleashed, the game that created the "boost" gameplay that was received so well, marred by an unnecessary and jarring "werehog" gameplay that no one asked for. Like, guys. You made a good game. Try believing in it sometime and not stuffing the rest of the game with other ****.