Is There Any Educational Value in a Pure Signalling World?

In a pure signalling world, the person going into the physics programme leaves no smarter and no better to do the job that i'd like to hire them from. But by me hiring from that pool, all those people are pre screened. So there can be actually no educational value in a pure signalling world but it can still be like an effective method. It's probably not good in the greater sense. But like both parties, in an economic sense, could be motivated to do something like that. I think, like a coding challenge, you know, this won't have anything to do with your job, but we know thatthe people who pass these seem to be able to do their jobs.