I don't reckon so, we know a great deal about Mozart and that he was incredibly productive throughout his working career which spanned 30 of his 35 years.
Thanks to Köchel and others essentially Mozart's entire life's work is very well documented and that over those 30 years he produced about 626 musical works most of which are of the highest standard, and of those some rank as works of sheer genius, not only have they stood the test of time but they still remain popular and well loved by millions some 233 after his death.
Mozart's talent and his life's work can thus be held up as a standard—a level of excellence—to which many of us would like to aspire.
What makes Mozart special, perhaps more so than many other famous composers, is how much he achieved in such a short life. He's up at the pinnacle with others who have achieved great things. Even for those of us who are not composers Mozart's yardstick can remind us of our own often-limited talents and work and how we wished they were better or how we might go about improving them. At times I experience such notions when listening to his music.