Is it feasible for the Switch 2 to have performance near Xbox Series S level at 400$?

[Oneeee-Chan!!!2.0]

Yes, it's possible, and
if many of the games of this gen can be ported, it should be close to the performance of Series S.

https://gamerant.com/switch-2-hardware-rumored-very-capable/

4k/30fps sounds better than Series S.
BTW Nexthandheld just said they confirmed 4k/30fps, the 30fps cap is a self-serving nuance by the reporter.

https://www.tomsguide.com/gaming/nintendo/nintendo-switch-2-docking-station-rumored-to-cap-performance-at-4k-and-30-fps