> the market seems to have decided that simple microwaves must be small microwaves.

Maybe I'm living in the wrong area of the world, I've never seen a differently sized microwave no matter the price category. They all are about large enough to fit a decently sized dish. Sure, the pizza from the local place won't fit, but that's not a microwave problem then.

> Want to heat something for 2 minutes 30 seconds?

Not really. In the 15 years I've had my ~$35 microwave (without a single issue I might add) I was never in a situation where I'd need much precision. Not to mention with every microwave, no matter the model, you need to have a feeling for how long to heat what in the first place. A lot of precision comes from that rather than beeping second counters.