Well it's hype would probably take Joaquin Phoenix's the Joker to win this time. Or probably close. I've only watched the Irishman and Jojo Rabbit, along with the Joker, and though I agree that they deserve to be considered, the latter movie takes it for me. I'm not sure about Waves and why it's having that much odds going for it. Probably I'll try watching it first and then judge which movie deserves to win more.
No doubt Joker was a box-office hit. It even broke Deadpool's record for being the highest-grossing R-rated film of all time. But I say critics' polarized response would play a huge role in determining what movie will get the Oscar. Some said the dark theme of Joker and how much it can inspire real-world violence can make it not get the Oscar for best picture, though I bet it will get awards in other categories.
I'm betting on Once Upon a Time in Hollywood. Star-studded, historical yet relevant, entertaining, and impactful.