Until we figure out a way to make lots of money from deep space missions, progress will be slow. The space race was, imo, mostly a race to optimize nuclear warhead delivery systems.
We probably would need to somehow uncover massive deposits of rare "earth" elements or similar to convince people to push for reaching to space seriously again.
Mining some Unobtainium from the asteroid belt seems to be the most plausible thing we can do in deep space that we can't do in LEO or right on the ground.