4k native = best image quality and the benchmark for DLSS to aim for. Will be interesting to see how many years it takes for DLSS to match native resolution without bugs.
Of course I'm forced to use DLSS on my 4090 to get FPS close to 100 in modern games, as the 4090 is too slow at native 4K. Though DLSS does have bugs and issues, visual artifacts with certain textures/areas in some games. It's improving, though still not close to native.
5090 will enable more games to be playable at 4K native, which is exciting to me