Yes, but Tesla was working decades ahead of these others.
True, but “State of the Art” has many meanings
The theory of the transistor was established in 1925, the the physical (pratical or working) transitor wasn’t assembled until 1947.
Absolute zero, it had to wait for better materials and technology (state of the art) - the list could go on - microwave or even modern radio...
Not to take anything from Tesla, he gave us polyphase AC after all - but a working ‘something’ is of greater value to Mankind than a theory - yes?