Roughly speaking, it takes anywhere between 5 and 15 years to become proficient in one of the classical music instruments, making it a very difficult skill for most of us.
But why not try and make music easier to play, similar to how cars evolved over time to make it easier to drive? As far as I can tell, instruments such as the piano haven't changed too much in the past 100 years, as even electronic pianos require about the same skills as their heavy wooden counterparts. Likewise the guitar looks about the same, with no attempts to make it more beginner-friendly. Even musical notation hasn't changed too much, requiring hundreds of hours of studying, even though we could now put a giant touch-screen display in front of every music player instead of being restricted to sheets of paper.
Or perhaps I'm wrong and there are indeed attempts to simplify musical instruments?