I am pretty sure the author mentions you only learn one third of every discipline of what you would normally study, so your invested time would actually end up the same. If you just wanted to learn calculus then you make a more valid point. (even though as I’m writing this, it seems to make sense to me to combine a Jenga tower topic calculus with boxed topics instead of Jenga tower topics if you’re not planning on learning any other Jenga tower topics.)
I am pretty sure the author mentions you only learn one third of every discipline of what you would normally study, so your invested time would actually end up the same. If you just wanted to learn calculus then you make a more valid point.
(even though as I’m writing this, it seems to make sense to me to combine a Jenga tower topic calculus with boxed topics instead of Jenga tower topics if you’re not planning on learning any other Jenga tower topics.)