Wii? From 2006? While true a more up-to-date example is the Switch JoyCon. It would have cost Apple like $0.40 to add an accelerometer so I don't think it was omitted because of cost. U1 chip omitted because of cost? Maybe, but I also doubt it. Even the aforementioned JoyCon "only" costs $40 which has far more technical functionality than the $60 remote. It's all just Apple being Apple.
*sigh*