Again I think this is a false dichotomy. Learning "everything ourselves" does not mean going out literally by yourself and rediscovering everything from first principles. Whether you learned it from a dreaded teacher or from a manual or reference or tutorial or a more senior engineer, you're leaning heavily on the accumulated body of knowledge and "thinkism" that produced that.

You will learn some things through trial and error entirely on your own of course, but you will also take a lot of time independently re-learning things that are well known. Which isn't necessarily a bad thing. I'm a huge DIYer. Sometimes you have to try and see for yourself. But I do acknowledge that I could have learned a lot faster about, e.g., carpentry, as an apprentice, than I did mucking about in my backyard with youtube videos. I think the concept of "balance" is more important than taking sides on this matter. They're both incredibly useful tools to be used in conjunction. Read the manual. Then go muck around. Then read the manual again and go, "oh now I get what they were talking about."

I think what I'm learning from this is that a lot of the "entirely self-taught" folks don't realize how much they've benefited from "thinkism" and standing on the shoulders of giants.