Teaching is mostly unskilled labor? What a ridiculous statement. Have you ever created a lesson plan? Written a test? These are difficult tasks that take skill and practice.
Driving a fork lift truck is skilled work. Plumbing a house is skilled work. Felling a tree is skilled work. I have never done any of these jobs but I believe the majority of work a teacher does has a lot more in common with this kind of labour than it does with, say, maintaining a web-based Rust build infrastructure.
*plural
I agree teachers are under-valued (both of my parents did that as a career), but a lot of the minutes of activity required when working as a teacher seem more aligned with the skills needed for baby-sitting than instruction.
I don’t know if it’s 85%, but from my experience in public school and observing/listening to my parents, it seems like it’s over half.