I do remember reading that Tesla felt he could improve on and fix those problems. It was his backers who felt it was useless, they couldn’t figure out how to charge for the power.
In my opinion, Tesla thought it could be worked out because in his day, the amount of power we now consume was beyond even his imagination.
He viewed the immense power of Niagara to greatly exceed any power we would ever want. In those parameters, the losses were not as important.
Today’s world is far different.
The technology works. It is in use and companies have expanded well past the phone charger on a plate. But physics have not changed, and the losses are still immense.
For more info:
http://spectrum.ieee.org/energywise/energy/the-smarter-grid/can-energous-deliver-on-wireless-power-promises
His backers couldn’t figure out how to make money on wireless power transmission. If you can make it work how do you charge customers who in theory would just turn on their electrical device and pull the power from the air.