Interesting point! Is this an Americanism?

I’m from northern Europe. I might use the micro to heat up leftovers or a cup of water for tea or whatever in a pinch, but in this household (and at all my friends’), the stove and the oven cooks the food. I know literally no-one who could say they cook most meals in the micro.

I didn’t have a microwave oven before we bought a house. It took up too much space to justify, for such a relatively rarely-used appliance.

American here, I haven't owned a microwave in over a decade.

I think OP is just an outlier.