The common thread you'll see among many people is that Sonic Games are inconsistent.
However, Sonic Mania / Generations / Boom: Shattered Crystal & Fire & Ice / Unleashed / Colors have proven that 3D sonic games can work and be excellent. It's just a matter of having an adequate sense of taste. Heck, 1/3 of Sonic 06 is good in terms of level design and exploration and if you have a doubt about that, you can go and play the fan re-creation demos.