The hours of dressing, whether by dandies or their forerunners in the eighteenth century whose costumes were so elaborate they required it, were of course not done by the rich and aristocrats themselves. They had small armies of servants, valets and femmes de chambre to work around them. Those could incur dreadful retribution if their movements pinched the gentleman or gentlewoman they were clothing, or if the "toilette" did not achieve the desired effect on its public, to the point that it was already a figure of satire in Marivaux's Île des Esclaves and many other plays. Beyond the need for such expensive and expansive hiring practices, fashion also had a major impact on economic life, and the turn to more restrained clothing could negatively impact a lot of people who designed and tailored fashion.
And you have the even more awful aspects. While I'm not aware of any particularly bad practice for the harvesting of purple dye beyond standard such things for the times, indigo was one of the major slave crops of the eighteenth century. I'm not aware of the particulars, but this endured beyond abolition and was a cause by oppressed peasantry, forced to grow it for paltry amounts of money, for revolts in India.