Read this article and agree on many of it's points. Have been here for some years now. If you've read just one of Patrick McKenzie / @patio11's articles on Japanese banking, you'll understand too.
There are also reports of the network adapters keeping the Switch from going into the lowes power state, thus keeping it somewhat warm. I had the same reasons as above though to not buy an adapter: I buy new games only very infrequently, so wireless is good enough for me.
Digital requires processing too.
As far as I understand the light sensing silicon is kind of analog, but even after that the camera can't see color just yet. Huge amount of processing is involved.