"I heard one person say that carrying fuel to land over the whole flight means it takes 23x more launches to get an equivalent payload to orbit."
I don't think that this is the case when using the atmosphere to shed most of your velocity, which is what we do when landing on Earth. Propulsive braking would be another story, but you can avoid that on bodies that do have some atmosphere. In our proximity, only the Moon and Mercury would need propulsive braking, but Moon's gravity is low and Mercury is hard to visit anyway.
That said, once you use the atmosphere to cushion what is basically a fall, the weight of the necessary heat shield comes to the equation too.
I don't think that this is the case when using the atmosphere to shed most of your velocity, which is what we do when landing on Earth. Propulsive braking would be another story, but you can avoid that on bodies that do have some atmosphere. In our proximity, only the Moon and Mercury would need propulsive braking, but Moon's gravity is low and Mercury is hard to visit anyway.
That said, once you use the atmosphere to cushion what is basically a fall, the weight of the necessary heat shield comes to the equation too.