Doing involves a lot of implicit knowledge that reading frequently fails to cover. There's a density of information in doing that reading sometimes lacks.
I would say there is no way to 100% cover with reading what you need to learn on the job. Also there is no way to cover some concepts with 100% on the job training (much harder to make a HS grad a petroleum engineer by just throwing them on a platform in the gulf without any formal education).
You have to have some implicit knowledge of how things work in order first...but that doesn't always come from formal education.
The challenges are compounded when two people come from very different experiences. The same words mean different things to them and then instead of fostering the transfer of knowledge, "the words get in the way."
I suspect this is a root cause of a lot of social and political friction. Doing or showing is sometimes the only hope of getting past that.
This is why most if not all trades have apprenticeships. You have to know what to do and all see what to do...otherwise you could screw something up because you misinterpreted the instructions or design.
There are good points and bad points to that.