Yeah the cross-platform situation makes things hard, but in a way it's the protocol's fault if it's hard to agree on things.

Also, I really remember Wiimotes failing to pair a lot of the time, but it was so long ago that I could be wrong. All I know for sure is last time I was at someone's house and they wanted to play Switch, it took like 10 minutes to get the controllers set up, but most of that was bad UI.