Another commenter already gave a great example, I grew up using a crt for gaming and I turn the filter on on a game by game basis. It really does improve the quality of some games. Other games do not rely on it as much.
Mostly game with detailed art look better with it.
There is an open source project that already does this a bit called box86 and box64.
I think you can find videos of people running Skyrim on arm chips like phones or maybe raspberry pi 5.
They don’t run well, but with more powerful chips and valves experience and money, I’m sure they can do it.