I’m spinning up a small side project, and started it out with vanilla JS and Node. Bundle sizes are tiny, startup times are fast, lots of concurrent connections, etc... But I really don’t enjoy the ecosystem or language, so am probably going to port it over to Clojure. Clojure has spoiled me. :/
For this you get the immutable data structures, and a decent chunk of the standard library, which you would use anyway.
On top of that, everything else that you get from the ClojureScript ecosystem, which is run through the Google Closure Compiler, is added incrementally. Use only one function, pay only for one (and its dependencies).
[0]: https://github.com/clojure/clojurescript/commit/5d64c2a142e5...
Backend is Clojure off course , though ClojureScript on the backend is starting to shape up as well, in case you're already familiar with the Node standard library and ecosystem. It can be a good alternative.
If you intend to only have trivial JS mixer in with your HTML, then better to go for a pure Clojure server side rendering with a few embedded JS snippets. Similar to what you'd do if using Ruby on Rails or Django.