I always wanted to use Racket in a bigger project to have a deeper understanding of macro/language creating. I always believe to achieve real 'domain driven design' is to create a layer of real business language which could interpret to a software system.
However, every time I want to do this I found Clojure is actually a much better choice. I guess to be fully practical is not #1 priority for Racket right now. But I really hope Racket can improve some of the following:
1. Encourage efficient data structures by default. I know lists are the soul of lisp but it's not good to use lists for everything. Clojure by default let you use highly optimized persistent data structures -- namely vectors and hash maps. These two data structures are highly practical, performant in most of the cases.
On the other hand, lists are more like write-heavy data structure, with really bad reading performance. This is like, a plain file system writes faster than databases, but most of the websites use a database because most of the business has much more reads than writes.
2. ClojureScript. JavaScript is a big thing until WASM fully arrives. Clojure has several really solid ClojureScript workflow, which makes me feel ClojureScript is really a first-class citizen.
3. IDE and debugging. I use Emacs + Geiser for editing, but Drracket for debugging. Drracket is really good, but still not great for editing hundreds of files. For Clojure, Cider and Cursive are IDEs makes me feel solid and complete.
4. Frameworks. I guess if the other 3 points are really good there would be many good frameworks come out every day.