C++ is a great language, used in most enterprise level of industries and open source communities alike, to build high performance and low resource applications. The language is very flexible and allows one to perform virtually any task one may want to. From building a web browser (Chromium), to building massive libraries (TensorFlow), C++ does a very good job as a tool to build them.
It is a very in-depth language and provides constructs and mechanisms for many concepts. One cannot learn the language by reading a book and it is a must to actually write programs and understand errors as they arrive to be able to understand the language and become proficient in it. And, always have the mindset of learning new things about the language. There is always a very high chance that C++ can surprise one with some nooks and crannies or features that it contains, so, it will take a long long time for someone to imbibe C++ into oneself. However, the journey is definitely rewarding, and fun.
Finally, in no way, is C++, a best language to use for everything. No language is, but one should understand when to use which language so that development is easier and work gets done efficiently.
Therefore, it is wise to work with other languages as well to improve understanding of programming in general and to be able to use the right tool at the right time.