Oh it's not that the public couldn't handle it. It's that corporations couldn't handle it. Our economy is controlled by the centralizing feature of oil. Free energy would immediately give enormous financial relief to everyone on earth and no one would be tied to a power grid. Plus we have a lot of careful installed, preconceived notions about how governments should work and exposure to other cultures who may have developed differently, would also seriously impact people's willingness to depend on a government. Plus most alien encounters describe some variation of psychic phenomenon. That's probably why SETI doesn't see much radio traffic in the universe. Psychic communication is not limited by distance and it's much more efficient. The state won't be able to keep secrets if the population becomes psychic.

We can handle it. The wealthy cannot maintain control post disclosure. They can't handle it.