Is it possible to be a Renaissance man today? One thing's for sure: it's a lot harder in modern times. In addition to there simply being more people in the world, the world is also a much larger place due to technological advances. In addition, free trade has resulted in exchange of ideas and goods with many more countries than Leonardo had at his disposal. We're more aware of other cultures, and we have a much larger skill base. Today, people are also generally more knowledgeable, and, as a result there's a lot more to know to become an expert in any particular field.
Leonardo was certainly one of the great painters of his day, but did he really have the same amount or level of competition that artists today have? How would he hold up against modern-day scientists? There's no easy answer there—nor do we need one. Leonardo's work speaks for itself. Even today, his breadth and depth of knowledge would set him apart. Given that, imagine what an astonishing figure he must have been 500 years ago! Suffice it to say that Leonardo was, in all respects, an original, and most likely would stand up well against any modern-day genius.