I don't think that's obvious at all. Learning is an active process. People listening to podcasts while doing work aren't going to actually develop some skill, they're just passively listening to some facts being thrown at them, much of it they probably won't even retain, let alone productively integrate.

You can listen to thousands of hours of guitar playing podcasts, it won't really help you play the guitar. Or you could listen to programming podcasts, but without ever writing a line of code you'd not be a any good as a programmer.