Opinions on the Series S? How much "worse" is it than the X?

I have a PS5, but am thinking of getting one of the Xbox series consoles because there are a couple of specific games I want to play (Microsoft Flight Simulator and Lost Odyssey for the 360). Also, it would be nice to have a Gamepass machine.

I don't mind the idea of having digital games, but I'm just curious how much of a drop the performance is from the Series X. Especially if anyone has played Flight Simulator on it. Have you regretted getting the Series S, or has it been okay?