The do need high frequencies. It's orders of magnitude slower than digital, but the amount of power being switched presents entirely new problems. You could flip your statement around and say that digital circuits are less complex because they're low power. But that would be equally meaningless.

Digital FETs are CMOS made with fins or whatever to switch as fast as possible. Analog FETs are something else to make clean predictable signals from mature manufacturing processes. Power FETs are big arrays of trenches to not destroy themselves. You can't really compare them. That would be like comparing a racecar to a passenger van to a rock hauler. They're all vehicles, but they have different purposes and success metrics.