It’s been an option for men forever, why shouldn’t it be an option for women too?
For hundreds of years, men have had the option of going to a custom tailor for a suit, blazer, overcoat, or shirts. London's Savile Row, the most famous custom suiting district in the world, was founded in the 1730s, to give you some idea of how long this has been going on. Presumably, aristocratic men had their tunics and other fancy medieval garb custom made before suits were really a thing, too.
Until recently this option hasn't readily been available