I bought a new microwave over the summer and so far I have only used one of the buttons on the thing: the Start button. The software on this $120 machine is impressive. I never read the manual, watched a tutorial, or anything. If you push the Start button it sets the timer at 30 seconds and starts. If you hold down the Start button it scrolls up in 30 second increments and starts after you release the button. The thing has all kinds of other fancy functionality but I doubt I will ever use it. An impressive design feat by GE, the maker of this particular machine.
I remember getting our first microwave oven in 1978. At the time it was probably the only computer in our house. It may in fact have been made by GE as well. It was a bit complicated to run in that you had to enter the power setting with a particular sequence of keystrokes, and then enter the time setting with another specific sequence, and then push start. It may have been possible without reading the manual, but read the manual we did.
The power setting, time setting, model was pretty consistent in all of the microwaves I owned for maybe 20 years. Then the power part seemed to fade away, and then quick minute idea came on the scene sometime over the past 10 years.
I bring this up because it is interesting that innovation in the microwave user interface sure seemed stalled for 20 years and then all of the sudden one big breakthrough. I suppose part of the equation is the training of microwave users that happened along the way, but I bet the biggest part of the slowness in change was due to the focus of the engineers. The turntable, lowering manufacturing cost, and other initiatives probably took priority. With a little effort, the quick minute button could have been added in 1980.
The one button on my iPad also does a different thing in different contexts. If the device is asleep, it turns it on. If an application is open it closes it… quite elegant. There is a big opportunity to invent technology that just works because someone spent the time to really think about how to make the one button work well. Now if someone could only do that with my TV remote.