One problem with this that wasn't as much of a problem in the 1970s is RF interference. The 1970s designs and many other designs use 2.45 GHz, so it will interfere with wifi and bluetooth, with bluetooth being more sensitive to interference.
How far does this interference extend? Thousands of kilometers from the receiver[0, see page 250]. Because the transmitter is far, the beam spreads out quite a bit due to diffraction and because the transmit power is gigawatts there's hundreds of megawatts of stray power. Making bluetooth headphones and bluetooth low energy tags work worse will probably make people angry.
Different frequencies could be used, but that requires allocating spectrum, which is a pretty difficult task politically. In the US, there are a couple bands in the sub-10 GHz range where power beaming works best that have few users. So it's not impossible, but still politically difficult.