Learning how to copy things is an art in and of itself. A lot of engineers (myself included) got into the craft by taking things apart and putting them back together again. It's true that you cannot become a good engineer /only/ by doing this, as at some point, you must learn how to create things from scratch that you've never taken apart and never put together before. It's true that teaches you a lot, but I think it's a little bit of a stretch to imply that it's the only thing that can teach you.
I’m not saying to pick one person and blindly follow them forever. It’s just a really fast way to get competent. I used the same technique to learn programming, scuba diving and sales. After you get the super basics down, find more teachers to copy and start even thinking for yourself a bit more.
It will take you surprisingly far, though. One thing I didn’t mention is it’s good for getting the most out of people who are master practitioners but not great teachers. Rather than ask them to take their skills and package them up for you, you just look over and make a copy for yourself.
To answer your point, there are times in the "learning curve" you need to get used to doing something, and then times to become exceptional. Compare learning to drive to formula 1. And commongcog has an article for that: https://commoncog.com/blog/get-numb-get-good/