Who Didn’t Jet Packs Ever Take Off?

The film above is from:

Jet Man, from the 1966 British Pathe reel “Jump Jet”. Filmed on location at Brands Hatch in Kent, UK.

It’s intersting to watch because the Jet pack operator seems to be in near total control. It’s always puzzled me that we were able to do these things in the 60s, but can’t widely do them today. I’d love to get the chance to use a jet pack. Anyone know why these never took off, aside from the obvious safety risks?