Yes. I mean if by better you mean better ballistic performance, yes composite bows shoot faster, farther and harder because:
Points 1, 2, and 3 mean composite bows store more energy, point 4 means composite bows use that energy more efficiently. This is true at all load factors, composite bows will generally always out shoot a longbow (given the same draw weight), even with heavier arrows though people generally assume longbows are better at heavy arrow shooting. It's just that their low virtual mass means composite bows are exceptionally good at shooting light arrows fast and far.
What the longbow does have going for it is that they're easy to make, a good bowyer could turn one out in just a couple of hours and the only maintenance it would need for its lifetime would be some oiling to protect the wood from moisture.
Meanwhile a composite bow takes months to make, sometimes as long as a year depending on the climate because the components have to be glued and let dry completely before adjustments to tillering can be made. Even after it's finished the the bow has to be shot and heat tillered for about a year, before the bow starts to shoot consistently without the limbs warping and flipping front to back. If the climate is humid, the bow will have to be kept in a special heated box to be able to keep the sinew dry for shooting. You pay for the extra performance with a much higher initial cost and require constant caring for.
I feel this is an odd question. The two bows might be somewhat similar in effect (i.e. shooting an arrow across a distance), but have different purposes. It's like asking if a sniper rifle is a better weapon than an assault rifle. They have two different battlefield uses.