[shreyashirday]

I don't think there's any practical benefit in "mastering" any particular language. In my opinion, it's much more useful to master certain concepts/fields or platforms. For example, instead of choosing to master either Node.js or Python, it would be more helpful to master server-side application development so that potential employers can rely on you to develop a well-written backend no matter what the language being used is.

Becoming an expert in C++ has little value because you have to also be good at applying that knowledge to certain fields, and that's especially true when almost every field (machine learning, application development, embedded systems, etc) has solutions that can be implemented in multiple languages.

TL;DR Don't focus too much on the language, focus more on the concepts of the field you want to work in :)