According to Stan Deyo, we have acquired the technology of anti-gravity but it was not released publicly because it would result in an economic collapse of the US, causing the collapse of other nations we are currently funding and rebuilding. This would result in a world disaster. It would not be released until an one world government exists because then and only then would the working people of the world feel safe in transitioning their jobs towards this new technology.

I found out about this perspective after I viewed Stan's anti-gravity presentation found here. This is very interesting and sounds promising but doesn't reveal why this information was never shared with the public.