I really enjoyed reading this article because it resonated so much. I'm a bit of a martial arts nerd, so I'm really into exploring in depth this concept (shoshin, as they call it in the context of Zen Buddhism).
I think it really takes some high level of self awareness to step away from our egos and start approaching what we do (even if it's something that we've been doing for very long time) with a beginner's mind. But, for all the reasons you developed in the article, I really believe it's worth it.
Hoping it doesn't sound spammy, I wrote a loosely related piece when I've just started in Medium (so I was an actual beginner!): https://broni-glez.medium.com/how-being-an-eternal-white-belt-helped-with-my-impostor-syndrome-5cc9d068f4a1