Right. What I'm saying is that any composer who would have struggled with Mozart's reputation would have very quickly hit up against a bigger problem: that nea

Right. What I'm saying is that any composer who would have struggled with Mozart's reputation would have very quickly hit up against a bigger problem: that nearly no other human beings have the capacity to remember, synthesize, and internalize the amount of music necessary to compose the way he did. That's why while Mozart was "grandfathered" into the Romantic period by early Romantic composers and writers, everyone emulated Beethoven in practice. At least obsessive motivic transformation is a tractable problem. (One which, btw, is a subset of Mozart's output.) Bach is in that same ballpark, though I'd argue that Mozart's output also includes examples of clear mastery of Bach's contrapuntal techniques.