I'm sure everybody knows Tesla, if anything because of Musk's cars
However, the greatest of all dreams of that dreamer that Tesla was, was indeed wireless electricity... it seems like that important steps have been taken towards that dream.
First, the concept of wireless is "tricky", since it implies the use of "no wires", which is actually something existing since long (my electric toothbrush has it, and it's at the least 5 years old) and as of today many portable devices can be charged wireless by direct contact or staying close to the charging pads
This video gives an overview of the actual systems and of what is the actual state of the art for wireless charging.
Tesla, of course, was referring to moving large amounts of electricity far away from the source, for every kind of usage (included heavy industry); while this is theoretically possible (I've seen some documentaries about transmitting electricity via the ground, for instance, and it works), the problem is that there's a large waste of energy compared to transmitting it via a confined mean (like a copper cable). As of today, the idea is to use the 5G network for transmitting amounts of energy enough for charging small portable devices, at the least. You can read more here.
However, it's not just a matter of efficiency, but of safety too. The video below is 4 years old, and not much has changed since then. Disney is involved in the project, and we all know how rich and powerful they are. The video is titled "Disney Invented A Room Where Your Phone Will Never Die", and as one of the comments brilliantly says "Your phone won't die, but you will" .
However, significant steps have been made in the recent times, and some realistic technologies are being tested, for instance in New Zealand. However, it might be early still, but I suggest them to find another name for what they named "rectennas"