He WAS rich for a long time. He died poor because he lost all the money on his ‘wireless electricity’ idea that noone wanted to fund, because they knew it’s not going to work. Tesla didn’t know that. You know why? Because he sucked ass at physics. That’s also why he would have never understood the concept of a transistor.
Please stop spreading misinformation about Tesla being some misunderstood genius screwed over by greedy corporations. He was not. He screwed himself over.