On one side, we are expected to work on topics in which we are experts
On the other side, our expertise tends to be narrower all the time.
This paradox (either narrow, but deep or wide, than shallow) is forced by the scientific environment. One is assessed on publications. Publications should be either seminal (once in twenty years) or they should further develop someone else ideas, it means they should deepen the topic. Ergo, narrower as a result.
What is your position on this paradox?