Is it harder to ride a comfort bike on a paved trail than a hybrid?
'Comfort' and 'hybrid' are not particually specific terms. Let's assume:

Comfort bike means a bike with an upright riding position - the rider's back is nearly vertical. Handlebars are high and relatively close to the rider.

Hybrid means a cross between a road and mountain bike rider's back 45-30 degrees from vertical. Bars far enough forward so that riders arms are nearly straight.

(Almost) all other things equal: wheel diameter, mass, tire width and pressure, the more upright riding position of the comfort bike makes it harder for the rider to apply power to the crank, hence it will be harder to ride at the same pace as the hybrid. The comfort bike will likely have a lower gear ratio range to accommodate the lower possible power.