Doen't the inverse square law show that more towers closer to the ground, even transmitting at a lower wattage, could be worse than a few towers high up and far away?

Just think about your handset, not the towers. The handset has to broadcast to those towers, at a power they can receive. As you hold that handset, to you want it to be broadcasting at low power to a nearby tower, or higher power to a tower further away? And who says that old tower is further away? It is going to be close to someone, even if it isn't you.