The best microwave I've ever used lived in the break room at my last job. It had one big knob, which worked like a standard kitchen timer: you would just twist it right until it pointed at the amount of time you want, then let it tick back down to the left until cooking was done. Want more? Just twist it right a little more, and let it keep ticking.
I have no idea why domestic microwaves come with a maze of buttons when such vastly superior knob technology exists.
Yeah, I've got a cheapo microwave, but honestly it's UI is pretty good as appliances go.
Turn the knob for time, hit ok, get power prompt, hit ok again for 100% (or adjust using the knob for less), microwaving starts.
There is also specific program functionality to tell it you have 200g of mince meat to defrost or whatever and it figures out the time/power setting, but I personally never use them.
They iterate over the design bits (black knobs on black microwave -> silver knobs on black microwave -> current design), but the microwave remains the same
Such knobs should be the most obvious interface but sadly most of the analogue models on the market lack a lot of accuracy. Some times even up to 30s-1min range. Enough to be the difference between cold or over-cooked food.
The best are often a big knob controlling a digital LCD timer. Started with a single start button doubling as +30s.
I have no idea why domestic microwaves come with a maze of buttons when such vastly superior knob technology exists.