I agree. Going back to the software dev field, because that's what I'm familiar with, there are people I know who are stuck in a sort of "tutorial hell" where they consume all these tutorials online, where you follow step by step with what the instructor is doing, thinking if they do enough of those they will get better and better.

Those are good to get you started with a technology, of course, but to really go to the next level, you need to untether yourself as soon as you get your basic footing and build your own thing. You need to get stuck and then bang your head for an hour or two figuring out how to get unstuck, repeatedly. You need to reach a dead end in the way you've initially set things up and have to refactor half your project to get back on track. That's how you truly master the skill. I imagine it's comparable in all disciplines.