Look at Space-X. I think we’d be further ahead, today, if NASA were shut down after Apollo.
I, too, was shocked by Challenger. The Columbia disaster made me realize that Challenger was a snapshot of NASA. They didn’t care, anymore.
In many ways, NASA was shut down after Apollo. That organizational slap in the face led to the shuttle being what it was. SpaceX got to be what it is and where it is largely by being a NASA contractor ... the latest in a long line of NASA contractors who built EVERY NASA LAUNCH VEHICLE EVER.