I ride a 24 speed and only use about 6-9 gears at all. It's about how you shift

Three speed is a difficult subject, now 9 speed is better. I think there is too many wasted parts into making a three speed but to make a 9 speed, that's where you get more efficient gearing. But still, 21 or 24 speeds are better, you just have to learn how to shift.