It’s useless advice to a student asking for specific help. A cooking student asking “why is my rice always soggy” should hear “let’s start by examining how much water you’re using”, not “watch more cooking shows until you understand through osmosis”.
The point of a teacher is to teach. If the only guidance they can muster is “consume more of what you’re trying to create”, there’s no point to having a class.
I've seen a lot of baseball and golf, and I still don't know how to even try to swing those things properly.
There is generally no "hack" that the student can use to avoid having to read a lot of stuff, in order to learn and especially to become an expert. What a student needs to read, isn't necessarily textbooks or the traditional orthodoxy of materials, but still there is undoubtedly a lot of reading that must be done, to "get good" as they say.
That being said, for a teacher to GUIDE that reading, to give some hints, pointers, themes, interconnections, sequencing (start with X, then read Y to deepen your knowledge of X), etc., is absolutely invaluable.
To me, this seems like the Pareto-optimal 80/20 breakdown, where 20% of the teacher's investment in time and energy can get you 80% of the benefit of having teaching at all (i.e. don't need a full curriculum or full-time commitment to dedicated instruction, but do need to spend some time/energy pointing the student in various directions and giving them some ideas to think about while reading).
Reading more would be reading problems. Doing practice problems is equivalent to writing and having someone/something point out if it's good or not.