I feel really bad for the people working in the drugstore now!

Just to be clear, the idea that weekly cyclicality in demand for labor, or any restriction on demand for labor hurts employee welfare makes little sense when the legislative efforts already focus on labor friendly restrictions on supply. In fact, one of the ways that unions served their members was by insisting that outmoded positions (eg. coal shoveler on a diesel-electric train) were still filled.

In general, labor interests are served when employers need more work done, and the supply of labor is constrained through things like limits to how many hours can be worked in a stretch without a break and when overtime pay is required. (I say in general, because everyone is also a consumer, so efficiency and productivity gains are not a net loss, they're a net gain)