In Napoleon's mind, he wasn't as much conquering Europe as liberating it from the clutches of nobility. Napoleon viewed himself as a better kind of dictator than the other European monarchs: one who rose to power through his own merit and who selected men for tasks based on their abilities, not their bloodlines. This narrative was decidedly less popular outside of France -- which had essentially executed all of its nobility in the preceding decades, so there was nobody left to disagree. But it really was a war of ideals over who should rule: an arbitrary (and increasingly inbred) line of inherited nobility, or the best man for the job?
If Napoleon had won at Waterloo, Europe would have saved itself a century of war. But the USA would also not exist in its current form -- much of the reason for the rise of American dominance in the 20th century was because Europe was rebuilt after WWII by the American war machine cranking out large quantities of steel and industrial machinery.
And who knows how the 20th century would have turned out without the US as a global superpower. Maybe without war and famine in 19th century Europe, there's never a migration and the central US remains as uninhabited as Siberia. It's fun to think of the "what if?" questions,