Lionel is still manufacturing and selling the CAB-1L remote as well as the orange Lionchief Universal Remote
First off, to head off the obvious path when you're boxed in, let's dispense with the CAB3 application. The whole premise of the discussion is one of having a physical remote with real controls, not a touch screen that you have to constantly look at to operate your trains.
As far as the CAB1L and the LC Universal Remote, neither of those options exploit many of the features of the modern Legacy locomotives. One of the more fun features for me is the combination of the train brake and throttle to create an infinite variety of labor effects. Also, features like the wheel slip for the Vision Line Big Boy and Challenger are not available using the CAB1L. Any feature that uses AUX3 is also not available using the CAB1L. All those limitations go double for the Universal Remote, with that control you can't even turn smoke on and off!
There's an old axiom in product design: Under promise and over deliver and you'll have happy customers.
Well, Lionel has delivered the CAB2 that has all the features described, and now they want to yank it back and hand me a much less capable remote control solution. That's over promising and under delivering, not the way to a happy customer.