"Exceptional times require exceptional people" "Talent without opportunity is talent lost"
Was 1789 an exceptional time? What if the financial/social problems of France had been solved in 1789 by those present at the time? No revolution. What then? Was Europe on the brink of another war of succession or expansion? The Potato War had not resulted in a general European War. Even in the midst of the actual fighting in 1793 and 1795, the partitioning of Poland did not result in another war between the parties. What upheaval might have brought to the forefront the men of both the Revolutionary Wars and the Napoleonic Wars?
Were the men who lead Europe in 1789 likely to be replaced by those who rose to eminence because of the revolution and later years?
If you look at where those men were in 1789, IMO, it is most unlikely that many, if indeed any, would have reach the pinnacles that they did. If Louis XVI had survived and then the natural succession of his family taken place, France would have been ruled by Louis XVII and so on.
Therefore, no Napoleon, no Robespierre, no Talleyrand, no Fouche, etc.
That they were men of talent, as history has shown us, is not disputed. That they may never have shown it to the extent that they did without the Revolution and subsequent events is perhaps more the issue, I think.