TNG episode "nth degree" should have changed everything.

It's the one were Barclay is blasted by a probe, becomes super-intelligent and takes the Enterprise to the centre of the galaxy to meet the Cytherians. The spend 10 days downloading information from one of the most advanced races in the galaxy. The impact of this should have been seen across the federation for decades. As an absolute bare minimum they should have acquired the technology to zip across the galaxy instantly without becoming mushroom farmers.

Instead it was a standalone episode that was never mentioned again.