Why this language is more important

Answer 1

Because its a prime language supporting oop, widely used, existing for a long time... blah blah blah... Thus Important

Answer 2

people are able to build Operating Sytem with this language. Linux. Do you know people ranging from age 5 to age 90(or more) use pc(that means they also need os for their task)
Probably more than 60% of world's population uses computers.. So think for a while.
Majority programs of Even Windows are build with c++.

Hope you understand the importance. Google : how c++ influence our life.