Mibu no ookami
Banned
Sony won't be a monopoly even if they are the last custom hardware console maker.
Those days are gone - competition for gaming dollars and time has never been so fierce, and consoles are not dominant in the current overall gaming context.
Sony have next to no gaming presence outside of their consoles, unlike for example MS.
You're not entirely wrong, but you're not entirely right either.
Sony with a console monopoly will do something they've never done before, operate a high margin firm. Those high margins are going to allow them to compete in other spaces like you've never seen before.
Reduced advertising budget on consoles, no more exclusive deals that pertain only to consoles... we're talking about hundreds of millions of dollars per year, if not billions in expenditure that Sony isn't going to spend toward competing with Microsoft.
Sony developing AAA titles so that they appear on console, PC, and handheld is going to give them a MUCH higher TAM, especially being the only premium console on the market.
Their games are going to go from selling 20 million as a ceiling to 30-35 million as a ceiling. We've already seen what they've been able to accomplish with Helldivers 2... They have a unique ability to focus on quality because they know they can push average games to sell 2-5 million copies on just PlayStation alone, and good games to sell 10+ million on console and PC.
Look at titles like Detroit Becomes Human, inFamous Second Son, and Day's Gone... these would have been absolute disasters on Xbox.