The French Revolution was more empowering than debilitating. Put another way, it awoke a sleeping giant.
At the time of the Revolution, France was the second most populous country in Europe (after Russia), and potentially the richest and strongest. The reason it failed to live up to this potential was the burdens placed on the French people by the various King Louis, especially the last one (XVI), and his wife, the extravagant Marie Antoinette.
The French Revolution eliminated these monarchs (and an oppressive nobility that ruled side-by-side with them) and thus freed a lot of resources for other purposes, including war. The Frenchmen were empowered by their newly-won freedoms, and their citizen-soldiers, led by a relative handful of veterans, fought bravely and well for many of the same reasons as newly empowered American revolutionaries some ten to fifteen years earlier, when led by many of these same professional soldiers, including one Marquis de Lafayette.
Put another way, the French had a natural quantitative superiority of resources against one or more coalition powers, and the French Revolution ensured that the quality of these resources would be at least equal, if not superior to the others.