You used frame generation, this post effectively has no point.
Whether it "looks the same" or not, you're still getting input latency equivalent to the REAL framerate, so if your PC is struggling to get 30-40fps, thats your actual input latency, which is absolutely abysmal to feel.
there is no such a thing as "30-40fps input latency"
input lag is different from engine to engine and even from game to game using the same engine.
it's different depending on the type of vsync you use, if you use vsync at all, and different depending on your GPU load even.
this means that in fact a lower framerate can have lower latency than a higher framerate, if the GPU is pushed to the edge of what it can render.
Spider-Man 2 on PS5 has lower input lag if you lock to 40fps than if you run the same mode unlocked. unlocked you can get maybe 5 to 10 fps more, but it will also absolutely max out the GPU load and this introduces more input lag than the locked 40fps mode.
this is why Nvidia Reflex literally limits your GPU load, which means it lowers your framerate on purpose, so that you get lower latency because the GPU and CPU run in sync instead of one of them having to wait for the other due to being run at absolutely maxed load.
in terms of Vsync, anyone owning a Steam Deck can try easily first hand how a simple thing like vsync can change your latency.
try running a game with a 30fps lock enabled in the game's settings menu, while keeping your Deck's settings at default. and then unlock the framerate in the game's settings and instead enable the Steam Deck's OS level 30fps cap.
chances are the Steam Deck's 30fps vsync has noticeably worse input lag than the games's own 30fps vsync. both 30fps, both triple buffer, but one is very noticeably worse.
the same phenomenon can be observed when modding say Bloodborne on PS4 and replacing the game's own 30fps vsync with Sony's API level 30fps cap. Sony's API level vsync will massively increase input lag. 75ms of additional lag to be precise...
in short, you can't give a blanket statement about input lag at any given frame rate, as there are 60fps games with more lag than other 30fps games. there are 120fps games with lag similar to some 60fps games.
example: Bloodborne on PS4 at 30fps has lower input lag than God of War on PS5 at 60fps, but if we would replace Bloodborne's own vsync with the aforementioned Sony API based one it would be God of War that would have way less latency.
if you want to make blanket statements about input lag, the only thing you can do is give your personal limit in milliseconds that you can tolerate. anything else is nonsensical.
if the game's latency is below your upper end of tolerable latency, who cares if frames are real or fake?
, then a bit of play.
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