In 2021, the Yamaha M1 as the fastest motorcycle around a grand prix race track. The evidence for that is clear: 2021 MotoGP world champion Fabio Quartararo. Quartararo had five race victories, more than anyone else, and five race fastest laps. He also had five pole positions, one less than Pecco Bagnaia.
So the bike was good, despite the chaos elsewhere making it look otherwise. Quartararo was the only constant in 2021. Valentino Rossi never managed to get his head around the new construction rear Michelins, and despite his protestations, was never the same after he returned from his bout with Covid-19. Maverick Viñales won a race, got another podium and a pole, but also finished last, tried to sabotage his engine, and left Yamaha after Austria.
Franco Morbidelli snapped a knee ligament riding a flat track bike, missed much of the season, and was still not fully fit when he returned. And the Petronas team saw a veritable parade of characters taking Morbidelli's place, culminating with Andrea Dovizioso, who is still struggling to adapt to the Yamaha, and to the Michelin rear tire he has never liked.