Other modern cars have an "eco display" or similar, which gamifies the experience. My previous car had some progress bars for different aspects, and I spent several boring commutes trying to get to a perfect 100%. (I did it once, I was so happy! Usually only got it to 98% before I hit the city and got stuck in traffic again)
Making automatics more efficient is a technological optimization problem. Making manuals more efficient is a human skill problem. I know which side I'd bet on in the long run. (Hint: Not the human)
That has the potential to be really dangerous though, at least where I drive(a third world country). If a car doesn't do what you expect it to when you provide a certain input, that's a recipe for disaster.
Large six cylinder revving to mid-range (say, 7500) with ample torque at all range can drive the car in overdrive even at city speeds, but an automatic will treat most change in throttle as a downshift. Because they have no ability to understand your intent.
I guess self driving car with an automatic can really fix that, especially because they can get geared optimally to the driving inputs the software tells them and they have 'inside brain' information.
My own anecdote is that I'm a better driver in a manual. I'm a lazy driver, and lazy in a manual means avoiding stopping/gear changes by anticipating green lights and so on. Being lazy in an automatic results in more stop and go for me because it's no more effort. I could be as efficient in an automatic, if I put in the effort (which I would probably do if I knew my numbers were going into a study).