IQ decent enough... Depending on the game, even 900p can look clean on my 43" 4K TV, like Mario Odyssey or Kirby ATFL, but games like Rise of the Tomb Raider, Batman AK or Zelda BOTW has too much shimmering due to the art style plus little. But these days I'll go from 1080p native to 1440p as minimum.
For frame rate I can't go below 60 fps and that's why I play primarily on PC, unless extreme cases, like some Nintendo bangers... But even those are paused after I beat last boss because I couldn't stand 30 fps anymore, current those are Zelda TOTK, Kirby ATFL and Xenoblade 3, two of them happily confirmed to get S2 upgrades.
Another weird case was Hellblade 2, I didn't want it to be blurry so I played 1440p native and locked the frame rate to 48 using RivaTuner. It was amazing, I'm actually willing to play games that way, as my TV is 144Hz for some reason 40 fps didn't feel good but 48 was smooth as butter.
For me Switch games look great graphically already, they just need better IQ, I think we already reached a sweet spot for graphics, I don't need them to be more realistic but with great art, IQ and frame rate.