My supervisor told me recently that it is very risky to focus on breakthrough topics except when you are doing PhD or if your are tenured. probably less true for PhD if you don't have ambitious PI. The demand for publications and results that is mainly the way to evaluate you starting from postdoc until tenure promotion is very tense. People usually try to do many things and stretch themselves. sometimes this even lead to burnout and many people leave academia for that adding to the very competitive and low gain opportunities available in most academic field.

To be honest, I really think that we have wrong metric. Most importantly, if you try to ignore them even if you get some local support within your group. Good luck getting any fund because funding agencies evaluation have the same problems.