Magic Bands vs TapuTapu is pretty trivial. TapuTapu can do more. But Disney isn't and wasn't concerned with how efficient FP+ was w/ the Magic Band nearly as much as they were concerned with crowd sourcing. Which, in turn, allows them to adjust staffing, ride ops, etc and make more money than they could have dreamed by reducing operating costs.
Park admission, dining, payment, room key, FP+, park-wide Wifi infrastructure, etc, etc- while it seems like a nice convenience was done so they can keep tabs on you in one concise program. Tiered pricing with efficient labor/ride allocation is leaps and bounds more advanced than Universal's. It's not even close. Crowds can "appear" less busy- because there are less people- yet wait times remain the same because they are able to adjust not only in real-time but with weeks of preparation.
The "business" aspect of FP/MM+ was brilliant. It seemed dumb at the time to spend a billion plus- one that people argued should have been spent on new rides- but it was never about "increasing crowds". It was always about getting more money from people "efficiently"- all while reducing operating costs. They've more than recouped their billion and are laughing all the way to the bank now.
As for TapuTapu- it's strictly a convenience factor for now. Long-term, I'd expect Universal to follow in Disney's footsteps as it has proven very successful financially.