Of Flying Cars and the Declining Rate of Profit

Where, in short, are the flying cars? Where are the force fields, tractor beams, teleportation pods, antigravity sleds, tricorders, immortality drugs, colonies on Mars, and all the other technological wonders any child growing up in the mid-to-late twentieth century assumed would exist by now?
A bit to the Left, but good questions all the same.

Of Flying Cars and the Declining Rate of Profit

"I assure you, there is very excellent services committed at the bridge."
- Fluellen, Henry V