I think I have tried 5 different models in the last few years, from the very cheap, to the relatively pricey, and all were relatively lacking when it came to fine control.
I don't think there's any real reason why they shouldn't have fine temperature control - presumably the temperature is controlled by the switching speed of the mosfets in the coils?
Are you sure you’ve used an induction stove and not just a regular electric stove?
Glass flat top electric stoves are not usually not induction stoves though they look the same.