A wireless controller contains a battery and electronics for a wireless connection, and yes, those are rather expensive components in a controller. Conversely, buttons are very cheap components.
Back in the day the GameCube's Wavebird controller was more expensive than the standard GC controller with a cord. Wireless has its price.
If you are bothered by prices of controllers, it's been common practice for generations to have high profit margins on them. No matter which console you've owned, you overpaid for a first party controller. Could the Switch NES controllers be $20 a piece? Of course, but pretty much all controllers could be $10 cheaper than they are sold for.
I get what you are saying. I am not sure how much production costs are for the controllers. It just feels worse since these controllers aren't an all purpose controller like the GC controller. (Though I do feel like the GC doesn't work well with a lot of games.) I don't know. Having an NES and Gamecube controller at the same price seems wrong. Then again I do not know what the production costs are for these contollers.