Some mods do require more performance from the console. The more mods you run the slower the frame rate gets at times. It obviously needs more cpu and gpu resources when you add extra elements to the gameplay and need additonal rendering. Switch would be fine for just changing textures and sound effects but if you give it additional tasks for the game engine to do surely its going to be difficult.
I don't think it needs it anyway. It looks to be a nice version and mods can be fun but there is so much content with Skyrim anyway. Tried out a few mods on the xbox one version of Fallout 4. Frame rate dropped significantly under heavy load and game become less stable. It was fun but in the end I went back to the standard game. I feel mods are best done on PC where you can have a PC capable of actually running the game easily and any additional requirements of the mods can be handled by the PC. PS4 and Xbox one have the games pretty much optimised to run as well as possible so when you introduce mods it can have a very negative effect on gameplay smoothness this would be even worse on Switch. Just don't see the point unless its merely textures and sound.
