Good for you. But some people need others to know that they are skilled to get a job or to be part of a community. You must be one of those priveleged ones moderately far along in your career that you don't need to worry about that.
The fact that you 'need' that is not an inviolable feature of the universe. It's not even a good thing. It's just a thing that has evolved based on the current arrangement of society. It's as mutable as whether or not we have regular religious crusades.
If you could see the quality of code I write or my career, you would likely change your assumption.