[the_hoser]

A microwave oven with two dials would still implement the timer and duty cycle control with software. You're just trading membrane buttons for stepper-motor backed rotary encoders. A neat luxury, for sure, but probably harder to keep clean.

[jaclaz]

The two dials are not necessary to be a a stepper motor backed rotary encoder, the timer could be a mechanical one, and of course the power setting could be a multiposition switch.

For the record I recently replaced one of them (mechanical timer) on an industrial grade dryng machine because a spring broke inside its clockwork, the machine (and the original timer) were manufactured 1978.

But, it could be a couple +/- buttons with TIME written on it and another couple buttons +/- with POWER, but then you would need a display, and then you would need backlight to it (people are reknown to cook in the dark), and then you would add a +10/-10 seconds button for daster setting the time, and possibly 4 or 5 "presets" buttons, each with a totally not understandable icon (is that a french baguette? But the setting is to just heat it a bit or to defrost it? and is that a pigeon, a chicken or a turkey?, etc.) or written in teeny-tiny fonts that the average user won't be able to read without spectacles ...

Compare this:

https://www.123rf.com/photo_33509347_close-up-of-modern-micr...

with - say - this:

https://www.123rf.com/photo_11190552_control-panel-wtite-mic...

[the_hoser]

A mechanical timer would be more expensive, and less reliable than a software solution. It would also be less accurate, but that doesn't really matter.

You could easily reduce the complexity of the actual controls, but it would still be a digital microwave.