The shuttle had reusable boosters, but if you are talking about something reusable that takes off and lands vertically you are correct that it isn't 1980s technology.
It's 1990s technology.
https://en.wikipedia.org/wiki/McDonnell_Douglas_DC-X?useskin...
No one denies that SpaceX has done good work. But claiming that they have done anything others considered impossible is just wrong. The basic principles had been demonstrated decades before.
You are correct that people criticized the economics. Seeing as SpaceX's prospectus shows their rocketry business loses money, I am not convinced they're winning that argument.