The musket might have revolutionised the battlefield, allowing relatively unskilled levees to become truly dominant. But up until the machine guns of the first world war stopped the cavalry in their tracks, the mounted horseman had a vital role to play in any conflict. The scale of the Napoleonic era armies resulted in a huge commitment to cavalry units.
Napoleon stated that “overall the numbers of cavalry in the French army will be 1/6 the strength of infantry”. At Austerlitz the french had over 11,000 cavalry men, at Wagram close to 30,000! It was more than a blunt instrument, it screened the army, it reconnoitered in advance and it would pursue and harass the enemy. Most importantly it was highly mobile.