Simple is easy when you’re a beginner — you don’t have much of a skill set, and so you stick to really elementary expressions of ideas. Because these ideas are still expressed in very shallow terms, executing on simple ideas when you’re a novice is really difficult.
As skill grows and expertise grows, another problem pops up. It’s easy to delude yourself into packing everything in your now colossal toolkit into what you’re building. This piling-on might have various causes: insecurity, arrogance, overindulgence, etc.
People who are really good at what they do make it seem easy, make it seem simple, make it seem ordinary and quotidien, something that could very easily be replicated. Roger Federer. Yo Yo Ma. Ernest Hemingway or Jhumpa Lahiri. I’d even venture to say DJ Mustard belongs in that category.
I think many people view experts as those with huge toolkits. But what really makes them great is that each tool is finely honed, and that they know the simplest/leanest combination of tools to use in any given situation.