I have an RTX 3060 that I bought about two years ago. Until recently I only had a 1080p 75Hz monitor, so I could play pretty much anything on max settings.
Then I decided to treat myself to a 1440p 180Hz monitor, which has been amazing. Obviously this is a lot more GPU intensive, so I have had to turn down some settings. Then I decided to try out FSR. I'm on Linux and gaming mostly through Proton, so it was as easy as adding a launch command.
Holy crap. Elden ring (admittedly not a very intensive game) went from a choppy 50 fps on high settings and medium ray tracing, to a smooth 60 fps on maxed out settings and high ray tracing with FSR Quality. And I can't even tell the difference from the upscaling! I'm super impressed and can't wait to try out FSR 2 and DLSS now!
The upscaling technologies they've been building into modern graphics stacks also have benefits for much older games where the performance isn't necessarily needed. There's an old game I like to play, Railroad Tycoon 2, which doesn't run at resolutions higher than 1024x768 and modern upscaling can make that game look absolutely gorgeous despite being 4+ pixels per original pixel.
I'm sure it provides similar benefits to emulators and the like too!