Depends on your natural ability as well. Scott Adams outlined an interesting heuristic, which is that for some/many people being the 80th percentile in five fie

Depends on your natural ability as well. Scott Adams outlined an interesting heuristic, which is that for some/many people being the 80th percentile in five fields can give you the same value as being, say, the .999th percentile in one. In addition, in some sense it can be easier to be the 80th percentile in five fields with hard work. Whereas being the .999th percentile in one can also require God given talent. I work as a data scientist who can do some development, stats, ML, design, writing, communication, econ. In any one of those I'm not a specialist.