Wasm is not an good compile target for it. It's made for C/C++/Rust type static, native-code languages. You would basically have to build the same kind of runtime environment implementation as you'd need for a native-code managed VM.
(That's why for example Python works well on WebAssembly - it comes with its own interpreter written in portable C that compiles nicely to WebAssembly, and uses reference counting for GC instead of a fancy GC).
Since Clojure is mainly a hosted language, a more likely avenue would be one of its current platforms gaining WebAssembly support. A Wasm JVM, or Wasm GraalVM target, for example.
I've been running a massive SaaS app for the last several years. JavaScript is not a performance problem, especially after compiling using the Google Closure compiler "advanced" mode. Rendering is a performance problem: think large tables. WASM would bring me no significant advantages.
