There are many negative aspects that come with supermodel job, like not getting paid a lot before being really famous, sometimes not having work all the year, strict diet and exercising to keep the shape, long hours and lot of standing, a job that can be done almost exclusively during 20-40s then models have to find a new…
I'd say most useless profession would be the managerial class in general. Before the labor struggles of the early 20th century, company hiearchies were much flatter. Worker, line-man, owner. Owner is some wealthy schmuck who doesn't show up, lineman is the boss, everyone else is your comrade. Made for much easier labor…