I do understand what you meant. I was just voicing out my own preferences on the matter. I find that characters with well stablished pasts i'm not immediately privy to are leagues more fascinating than your usual blank slate protagonist, which is generally a clutch for storytelling to excuse info dumps. This is done so many times, and those characters often turn out way too ignorant or naive, thus i revel when a narritive actually challenges my own intellect as a reader. I do think that i'm of a minority in this regard though, as i see a lot more people who dig in the self insert protag cause it helps them relate to the story. It's just that doesn't work well with me, these self inserts feel more like non-characters as they have little to no remarkable traits. At the end of the day it's all a matter of preference.
also i just felt like trying to theorize about the magic system out here, you seemed interested in the topic at the very least.