Just a guess, but based on your comment that you can't "justify moving away from Python or C", I suspect you've never moved much beyond procedural programming,

Just a guess, but based on your comment that you can't "justify moving away from Python or C", I suspect you've never moved much beyond procedural programming, possibly with a bit of OOP mixed in. If you stick with procedural programming (and it's perfectly fine to do so), then it's true that most languages will not offer you much that Python and C cannot. If you're willing to re-think how you model the problems you're solving, you may find other languages, such as Clojure, help immensely.