Simple really. Spending all that money on R&D for a next-gen console only to have it limited by the previous generation would be a monumental failure. And it will be limited. As I said before, the X1X is capable of more than what it is doing. Next-gen would be the same. There is a big difference doing this as a mid-gen refresh and doing it for a new generation.
They spend all that money for R&D to create a closed system PC with off the shelf parts that they can manufacture at a digestible consumer price because enthusiast gamers want the best textures, lighting, resolution and frame rate. If they don’t keep offering that to enthusiast gamers, they’ll lose them.
No publisher likes the temporary dividing of the base in the first few years.
They make jack on hardware. Biggest margins are services...and services are held together by community and keeping ecosystem unified. Next is software. Then accessories. Microsoft would rather sell you 3 months of Game Pass than one hardware upgrade if that hardware upgrade isn’t necessary to keep you plugged in.
Aim up, scale down. Not limited. There is no magic alien technology around the corner. The Zen CPU of 2020 will not be capable of upping frame rates, lighting and still have head room for true evolutions of physics and AI at the same time. That R&D going into physics and AI is to leverage cloud compute...which is coming to every damned industry in a few years. You want to be excited about Ray Tracing lighting, next generation AI and full scale destructability in single player games? Be excited about those things but realize that local hardware will not get you there in 2 years. That will only happen with cloud compute.
Game engines are all built with scalability in mind because developers need to cast a wide net. If the game engine doesn’t, it’s crap.
God of War running on a launch PS4 looks better than almost anything running on a top of the line PC minus resolution and frame rate. That’s because Sony invested insane money into it. Budget, not hardware, is the most limiting factor in pushing the envelope.
Will it be worth it to scale? Yes. It takes a fraction of the resources to scale down and if the base is still there, they will. Microsoft and Sony will not be releasing games that cost $100 million+ to make to a base of gamers under 10 million if they don’t have to. They no longer have to.