Why? Being an introvert is not a weakness or a flaw, it is simply a fact of your being. Much like the kind of hair you have or the timber of your voice.
Are there certain kinds of hair that are more popular in this world? Sure. Can you dye your hair blond and condition it and grow it and get a great haircut so it becomes something that is admired by others? Sure. Will that give you advantages in terms of career benefits and popularity? Sure. Is it authentically you? Nope. Will there be people who would prefer you with your normal hair, people who like and love you as you are? Sure. Will that not be more satisfying?
You can train yourself to speak more in company, improve your vocabulary, learn three different languages. You can learn to dress better, play the guitar, and dance like a boss. These are just skills that anyone can hone. It depends on what you want to achieve. Some of them will give you a lot of career advantages, others will give you personal advantages.
But in the end, every so often, if you are a true introvert, you will seek solitude. You can call it meditation or zen or reflection. It is a moment when you want to shut out the stimuli from outside you, and calm the swirling emotions within you. Imagine yourself as a container of water, and as you interact with the world outside, people shake and tilt you. They throw stones and dirt and color in you. The water is turbulent and murky and by the end of the day, it is swirling with debris. Until you are alone, and you let the water calm down. All the extraneous stuff either sinks to the bottom or floats to the top and the water becomes clear again. And if you want you can clean away all the stuff and become pure again, ready to face the world.
So there is nothing weak about being an introvert. It’s just a fact of life. It won’t prevent you from achieving what you want. It may make some things harder, but will make other things easier. Get to know yourself. Try to understand what you want. See what skills you need to get your goals. Work on those skills. Don’t try to be someone you aren’t.
Accept yourself. Get to know yourself. It’s pretty cool to be an introvert. You are less dependent on others, less needy for popularity.