>>2469not sure if bait or just misinformed.
Regarding the OP...If someone practices for 18 years, diligently improving their art every step of the way, mastering the fundamentals of painting and drawing, as well as learning a shit ton about how the world and its inhabitant are put together, you will be able to make beautiful art.
But you don't need to do that if you don't want to. There are other forms of beauty. A manga artist only needs to draw well enough for clear, visual communication of the story. Any difference in art after that comes down to taste.
People eventually start to become the artist they were meant to be, imo, as long as they do it for long enough, create a pure practice, and don't stubbornly stick to schools of thought that aren't for them (like hammering nails into their thigh every-time they practice). Hence why the best artists are all so unique. Sticking to it for countless years is either a sign that you were meant to be an artist, you enjoy being an artist, or have some extraordinary stubbornness. And if you enjoy being an artist and making/studying art, that is all that really matters.