Depends on the game. Some stuff is fine even at 30, other stuff framerate is king. Playing FH4 at locked in at half-sync (72 fps) on my 144Hz display is sooooooooooooooo goooooooooood
Some stuff may be fine at 30fps, but it's noticeably better when moving to a higher frame rate.
I've been playing Dark Souls on Switch and it plays fine. Then I fired up Dark Souls and Dark Souls 3 on PC, and it's a night and day difference in how much better they feel.