The guidelines' purpose is to assist users in efficiently using contemporary C++. We refer to C++11, C++14, and C++17 as "modern C++." In other words, assuming you can start today, how would you like your code to appear in five years? 10 years from now?
Interfaces, resource management, memory management, and concurrency are some of the higher-level topics that are the emphasis of the guidelines. These guidelines have an impact on library and application architecture. Following the guidelines will result in code that is much more likely to catch programming logic problems than is typical in today's code, is statically type-safe, has no resource leaks, and more. It will operate quickly, so you can afford to do things correctly.