After the soul leaves the body, it enjoys the pleasures of being disembodied and not having to schlep a body around. But the soul leaves the body gradually because during life they become very attached to each other. To some degree the soul never completely gives up on its body, even after the body has decomposed. That’s why going to the gravesite where the body is buried enables us to communicate with the soul better than anywhere else. To some degree the soul is still hung up on its body.
But there’s also the concept of Resurrection. Someday that body will be resurrected and the soul will come back to its body because it never gave up on it. The body that helps you serve God has acquired some holiness that will never be lost and the body deserves a reward just as much as the soul because without a body you can’t do mitzvahs. A soul cannot put on tefillin, a soul cannot eat matzah, a soul cannot light a Shabbos candle or go to the mikveh, so without the body the soul can’t do any of the mitzvahs. Why then should only the soul be rewarded in heaven without the body when the body is more than 60% of the mitzvot? That is why we believe that there will come a time when the body will get its reward by being resurrected and reunited with its soul and live forever.
The pleasure of being a soul is a much greater pleasure than having to carry a body around. But on the other hand, for a soul whose entire existence is to serve its creator, in heaven it’s frustrated it can’t serve God. On earth, we serve God, but in heaven you are served and God gives you the pleasure and the reward for everything. But the soul wants to come back and be needed rather than needy in heaven. In heaven, you’re not needed, you’re rewarded. The souls in heaven are waiting for Mashiach so that they can come back into their bodies.
Heaven is not the ultimate goal in Judaism, it’s a holding pattern until the world becomes a little nicer and a little godlier, the soul will stay in heaven. But as soon as the world is ready, the soul wants to come back live on earth and serve God. Because it has no ego, it doesn’t want to be served. It wants to do the service.