And Ice Cream stores as well. One of the things I have just learnt from cocaaladioxine's comments on my post was that you actually don't need the worker card.
It honestly blew my mind as I had thought that it was a necessary component of the game and had been buying worker cards to staff those job positions. But now that I know that you can just use your popularity to increase the population of your city and staff positions that way, it seems to be better to buying popular, income producing buildings instead.
So I am putting up a bunch of workers on sale on the market and with the funds, I am buying music and ice-cream stores.
So why would you even need worker cards? One reason would be to perfectly balance the population of your city. You'd need some fine-grain control.
Seems like there is a worker shortage and the price of workers has gone up in recent days.