You can be a pretty good artist if you draw what is around you. Many people do very well this way. The Hudson River Valley School being a prime example of this. I think you'll find, however, that the most famous and successful artists create their subjects. Michaelangelo's Sistene Chapel comes to mind. Portraits are the exception. Capturing the human form in all its subtelty is very tricky, human emotion is elusive. But, back to the creation thing, I believe that surrealism is one of my favorite examples of this, yet it often is based on reality. Salvador Dali had a self portrait, his face was oozing and being held up by crutches, as his paintings so often are, but it is very impressive. I would say it were a real thing, if not for the fact that it isn't. Perhaps that is what makes their paintings so good and realistic. Whatever they are painting really exists for them. The universe bends in their mind to make it that way. Art is cool.