While Tesla was researching wireless electricity, he was being supported by JP Morgan. Morgan had an interest in what was then a monopoly on copper. That monopoly wanted their copper wires to rule the world, not free wireless power. Tesla's vision of helping humanity didn't fit into the designs of a monopoly, so Morgan made sure Tesla's research went nowhere.
As Morgan said, "If anyone can draw on the power, where do we put the meter?" Tesla's mistake, as brilliant as he was, was his inability or unwillingness to see how the Dogs of Money keep all the good scraps for themselves. I know many brilliant people today with the same difficulty.