And to those who say that a Napoleonic victory at Waterloo would not have made any difference, I'd only reply that it's generally a bad idea to underestimate Napoleon. Considering how well he did during the 1814 campaign in France against much longer odds than he would have faced in 1815 suggests that he had at least a shot at victory.
It seems that you are missing something fundamental: in 1814
he was doing just great all the way until he found himself strategically defeated. He could not be everywhere at the same time and the Allies already figured out how to advance on a wide front making his personal victories pretty much pointless. In 1815 situation was pretty much the same and addition of Davout (not to mention clown like Murat) would not change things strategically.
According to Clausewitz (
https://www.clausewitz.com/readings/1815/five1-9.htm) who was, beyond any doubt, a good authority on the issue, in 1815 he
really had 217,000 troops (he boasted about the great reserves but they did not materialize) vs. total 600 - 700K of the allied troops marching to France. To quote from the original "However confident he may have been about his rearmament efforts, he foresaw that before he could complete them, an enormously superior force would advance against him. He personally believed that 600,000 men would oppose him, but in fact between 600,000 and 700,000 appeared. If we compare these numbers with the 200,000 that he had in the field and add to them another 50,000 who were in the fortresses with which the enemy would come into contact, there still remains a superiority in numbers that even a Bonaparte had reason to fear."
Further: "In the first half of June, the forces that the Allies set into motion against Bonaparte had the following strengths and dispositions:
1. The army of the Netherlands
Wellington in Belgium
consisting of English, Hanoverian, Dutch,
Brunswick, and Nassau troops
100,000
Blücher on the Meuse
115,000
Germanic Confederation troops on the Moselle
20,000
Total
235,000
2. The Russian army, on the march towards the Middle Rhine
140,000
3. The Austrian army, together with Germanic Confederation
troops from Southern Germany, on the Upper Rhine
230,000
4. The Austrians and Sardinians in Italy
60,000
[Grand] Total
665,000
Against these masses the French had approximately:
Standing Army
180,000
National Guard
15,000
Total in the field
195,000
If we add to these about 80,000 men from the fortress garrisons, who could have come into action during the course of the campaign, then the French with their 275,000 men are supposed to hold their own against 665,000 men or even defeat them. But the Prussians alone had another 100,000 troops moving up, namely the Guard, the 5th and 6th Corps, and several regiments belonging to the other four corps. Later on, the Neapolitan and Danish troops would have to be taken into account as well, along with the new corps being raised in Germany, such as the Prussian 7th Corps in Westphalia."