British recruitment was very different from French conscription.
Like learning to read, martial training had once been a privilege of the aristocracy. Even by the Industrial Revolution, it remained the right of the "propertied classes."
Medieval knights had to provide their own armor and horses. Only Robin Hood used cheap, readily available bows and arrows as weapons. With Napoleon's rise, uniforms replaced armor and became a fashion in men's clothing.
Students going to Hogwarts had to visit Madam Malkin's Robes for All Occasions to have their school robes made, and young British men joining the army also had to pay for their own uniforms. It was said that a soldier's outfit cost fifty pounds at the time, with another ten pounds a year needed for upkeep. A yeoman farmer's uniform was relatively cheaper, but it still cost ten pounds—not to mention the splendid uniforms of those dukes.
French conscription, on the other hand, targeted bachelors regardless of background. Anyone who wanted to avoid military service had to pay a tax, which doubled after the Seven Years' War. Uniforms under the Bourbon dynasty were not as good as those of Napoleon's era, and the soldiers' food was terrible as well. The state paid for all of it, as part of military expenditure.
France's national conditions were utterly different from Britain's. France was an agricultural power with a larger population, and its Industrial Revolution profited from vast numbers of cheap laborers.
Britain, meanwhile, did not have that many people. With so many foreign wars and overseas colonies, once those serving as soldiers or working the land were excluded, the population available for industry was very limited. Under such circumstances, Britain's Industrial Revolution relied more on machinery than manpower.
Although many men in the Victorian era had mistresses, they only ever had one