Good question, though doing technical tricks at a young age does not make one Mozart. I don't mean that we don't have 1000 composers as good as Mozart or Beethoven. I mean we don't have 1000 composers recognized as being that good. We may very well have 10,000 composers better than Mozart, but we're unable to recognize that many good composers.

This is conflated with questions of high versus pop art andd accidents of history. Personally, I'm open to the idea that Mozart represents a temporary decline in musical taste--a period between baroque and romantic when people ate up the kind of pleasant, predictable pop music that Mozart churned out. He wrote some great stuff, but I think the bulk of what he wrote is soulless compared to equally-prominent baroque or romantic music.