Personally, when I see unfamiliar code (in any language) and try to figure out what it does and how to fix or extend it, I'm not sure "fancy" vs "junior" is what breaks me. It's things like documentation, naming, explicitness. I wonder if your notion of "fancy" is orthogonal or correlated to these qualities.
Regarding https://www.parsonsmatt.org/2019/12/26/write_junior_code.html, it might be helpful to provide concrete examples of "fancy" code and "junior" code doing the same sort of thing.
Personally, when I see unfamiliar code (in any language) and try to figure out what it does and how to fix or extend it, I'm not sure "fancy" vs "junior" is what breaks me. It's things like documentation, naming, explicitness. I wonder if your notion of "fancy" is orthogonal or correlated to these qualities.