> Musicians get better by practice and tackling harder and harder pieces, not by switching instruments or genres, nor by learning more and varied easy pieces.

> Musicians get better by practice and tackling harder and harder pieces, not by switching instruments or genres, nor by learning more and varied easy pieces. I wouldn't agree with this statement in the first place. Switching instrument or style gives you a different perspective on music, and the same applies to software engineering. If we want to go on with metaphors, 100 m dash runners don't only repeatedly run 100 m again and again during trainings. They do long runs, interval traings, weight lifting and much more. Of course, diving deeper is necessary if you want to become expert in a field, but this doesn't mean excursions are not helpful too.