Really? Sonic Forces is what does it for you?
The alarm bells have been ringing for years man
Obviously, we pulled out of the dark age for a bit with Colours and Generations, but that was more luck than anything. They took away the wrong things from that encounter and (among other things) brought back Classic Sonic for Forces for no reason when:
He was undeniably the weakest aspect of Generations
We had actual, authentic Classic Sonic in that same year, which rendered this return entirely unnecessary, making it feel like a desperate attempt to get people to buy the game and pad out the length (which is fair as there would've probably only been like an hour and a half worth of game otherwise )
He has no reason to be in the game anyway - he's not even from the past anymore like, what? Are they just high? It was like bringing back the Wisps in Lost World - they make up a thing and then they just forget its backstory in the next game and just use it because "uhh oh this game had it and it worked right?"
Lost World in general was bizarre, but it was more experimental so eh, whatever. Boom was just a stupid idea to let it get greenlit, when clearly neither of the groups working on their respective games really knew what they were doing. Mania only worked because they pooled together people with actual talent and passion to create it, which is probably the smartest thing they've done so far. And that pretty much sums up the recent stuff. Sonic 4 as well, actually, was minor fail too. The handheld market was doing fine there, but, whatever I guess.
The dark age speaks for itself. That was just... it was just abhorrent. Over the course of about three (or four, depending on who you ask) years they managed to pump out more garbage than the worst games of like any other franchise combined
So no, they haven't known what they were doing for a long time.