I suppose if 30fps is acceptable. I don't think it is - I'd take an upscaled 60fps every time, but I'm quite sensitive to stutter. It really irks me.
They can do 4k60 in many cases, but with dynamic detail levels that hope you don't notice what's not in the centre of the screen being lower fidelity. Assassin's Creed Valhalla looks... interesting that way, and Ubi is probably the best in the market at the technique. That said, I've only seen what the PS5 can do. The Xbox is a smidge more powerful so may be better at it.
But back the to Switch... The current one can't do 2k30 in most cases, the next one would need at least 5x better performance just to do 4k30. In a portable shell. I reckon if Apple provides the next Switch CPU it could happen, but that's pretty unlikely.