I'm no rocket scientist but I could imagine rockets having a place in regular space travel. Lets assume that we can harness solar power efficiently and safely store the extra energy in hydrogen and oxygen gas. Then let's say that we could construct sturdy and modular components that can be disassembled and re-assembled at some kind of orbital station, so that the boosters that take people into orbit for whatever reason could be rebuilt in orbit to carry a load of asteroid-mined metals back to the surface.
Again, I don't know any of the mechanics or physics, but if energy was abundant and parts could be reused, would rockets really be all that bad?
Fuel is a small part of the cost of a rocket, most of the cost is in the engines and structures. Cheap production of hydrogen or oxygen is unlikely to make things much cheaper.
Also, any mass left over at engine cut-off requires a large quantity of fuel at lift-off and possibly necessitating a larger more expensive rocket. This would make re-purposing of boosters in orbit less likely.
Again, I don't know any of the mechanics or physics, but if energy was abundant and parts could be reused, would rockets really be all that bad?