Javascript is the king ♔ ! Honnestly, the learning curve in python is low compared to node. There is no python -fatigue. When you chose python, you know where you are going for the next 2 years. And, you have to learn so many concepts that are language/écosystem indépendant. So if you are new in dev, python is the best choice. But, if you have an experience of 2 or 3 years, javascript is a good second language to learn.
Cheers !