Richard Hamming gave a very influential lecture called “You and your research” — there are a few versions of it online and it’s been discussed here a few times

Richard Hamming gave a very influential lecture called “You and your research” — there are a few versions of it online and it’s been discussed here a few times before. He poses the same question in pretty much the same way, “why aren’t you working on the most important questions in your field?” I would say that what he defines as “important” is along the lines of “what will be the most influential?” - the sorts of things that bring Nobel prizes and glory. But no one can tell you what is important: it depends on your own values; it’s a question you have to ask yourself.