How dependent were the ancient Romans on slaves?

The Romans like all ancient societies were very dependent on slaves. Slaves were the automation of ancient societies. As all work had to be done by hand, many hands were needed to complete a project and slaves were those hands. Domestic slaves took care of house business and if their owner had more than one house a slave would be in total charge of one or more of them. A businessman would employ slaves as Accountants, secretaries or assistants and of course, there were the personal valet slaves who took care of clothing, hairdressing, and all personal grooming.