I think the problem with space exploration is simply that we are primitive, we only understand things which give us economic benefits within a decade. Going to space is just something we have to do on a longer scale, hundreds of years. Not doing it is equivalent of a tribe staying within a few miles of their village generation after generation. In the long run, they won’t survive and they certainly won’t prosper and be great.
By the way, I’m reading the “Bobiverse” series by Dennis E. Taylor. It’s excellent hard SF about robotised human minds colonizing other systems. Funny too.