30fps and 40fps modes are usually running at native 4K and drop (resolution) very little when they do. While 60fps modes can run down to 1080p, they mostly run at 1440p (or not far below) then reconstructed to 4K.Rift Apart benefits fairly little from switching from 60fps to 30fps mode. Clearly the 1080p->4k reconstruction method Insomniac uses is very good.
But a developer would give themselves twice the overhead if they targeted their game to do 30fps at 1080p->4k reconstruction. You can *always* do a lot more at 30fps relative to a given 60fps situation. Always. And I can never, ever see developers just giving up this competitive advantage. I think people underestimate just how much of an arms race exists between developers in the graphics area, as this totally sells games.
Maybe console gamers will just get so used to 60fps that they can never go back, but I really doubt it. Console gamers love to drool over graphics. And when even I can enjoy a 30fps game just fine, despite playing the vast majority of games at 60fps on PC, I'm pretty sure people primarily play on consoles will be able to adjust back just fine.
This was always a very silly expectation.
And you always have to trade fidelity for framerates. You can never have it all in a fixed spec scenario. There is no genuinely no way around this. It will be the same situation with the next generation in 2028 or whatever.
You clearly didn't play the game yourself.