1. You cannot touch the sacred cow $60 game price. You can go lower, you cannot go higher.
2. Reoccurring revenue & upsells/addons are every business' wet dreams. The game is done, sell it at $60 and shift 9/10ths of the team onto the next game. 1/10th of the team remains in bug-fix/content-churn mode to fulfill whatever season/battle pass scheme they're peddling. Release a new game with the same stuff ~2-4 years later.
3. Singleplayer games are dead because studios haven't figured out to get cheap secondary/ternary monetization out of them (for cheap.) A lot easier to make a digital hat than keep your design/narrative team making expansions.
To address the actual post: Amazon is hopping on because they have the technical capabilities... Unfortunately they don't have the game-industry/consumer-oriented know-how to make this a success. It's going to be a 'neat tech demo' but they'll never get a foothold because it's not solving an actual problem consumers are having at the moment.