The best part of learning piano isn't getting good at piano---it's learning piano. And sure there are some things we have to learn that we aren't that interested in learning, but I think even those things have the capacity to be worthwhile experiences if properly framed.
I think applying the word "efficient" to this area is suggestive of urgency and greater purpose---I don't buy into either.
And I think greater purpose is definitely a thing if you subscribe to a utilitarian moral framework
I graduated in mathematics. Proving that Projective Space is a noetherian scheme is not exactly a thrilling challenge. But you have to go through the motions if you want to be able to "think" about algebraic varieties.
Same in any other field of "knowledge".
Who is doing that?