I might be misinterpreting your post but it sounds like you’re talking a little bit more about confidence. The key to having confidence and fighting away imposter syndrome is to find and focus on the positives, how you got to the spot you’re in and all of the times you’ve had to succeed. Forget about the failures and spend time every day reflecting on your accomplishments.
It’s that simple. You don’t even need to believe the stuff you tell yourself, but if you keep repeating it to yourself, you will start the believe it. Confidence requires active effort to build, independent of how good at something someone is. I struggled with my confidence and occasionally still do but had a friend recommend a good book that legitimately changed how I view myself. I can’t remember the name of it off the top of my head but if you want I will look it up and edit my comment.
Fair enough, I don’t think I have an direct answer to the big picture of your question but in my own experience improving my confidence and the mentality I’ve adopted to do so has in turn reshaped how I view myself. So as you stated there might be an overlap of the two topics.
I’m not trying to advertise it (I have it as a pdf and would offer to send you a copy if I knew how to do that on here) but the book i was referring to is called “The confident mind” It’s by Nate Zinsser. It felt a little dry but it isn’t trying to be a science fiction novel and makes it points very well. An example being from my last comment just repeating something to yourself over and over leads to you starting to believe it. It also uses pro athletes and their mentality and talk about how one could apply the same approach to everyday life. It’s not earth shattering revelations, but for me it did connect things in a way that helped shift my perspective.