Yeah, the narrower tires weigh less and have very slightly less rolling resistance. They also create less air drag.

But you're right that there is a tendency to put the narrower tires on "road" bikes, even if they're clearly not "competition" class. I suspect that this is because, like several other aspects of a bike, the narrow tires are simply perceived (by most) as "better" and perhaps "sexier", and so they look better on the show room floor.

Yeah, the narrower tires weigh less and have very slightly less rolling resistance. They also create less air drag.

But you're right that there is a tendency to put the narrower tires on "road" bikes, even if they're clearly not "competition" class. I suspect that this is because, like several other aspects of a bike, the narrow tires are simply perceived (by most) as "better" and perhaps "sexier", and so they look better on the show room floor.

(And note that a cheap bike is apt to have 23mm tires rated at 85psi -- lower than optimal for many situations, while a better bike might have 27mm tires rated at 105psi. I run my 35mm tires at 100psi.)