When I was last at a Java shop, we we're pushing multiple-thousand line PRs every week, a good 40% of those lines were simply boilerplate generated by IntelliJ, and it would have been worse had we not fully instrumented our codebase with Lombok, and all this was for a pretty mature product that wasn't seeing any radical changes from day to day. At the clojure shops I've worked at since, we're building more and delivering product faster, and we're doing it on the JVM with less than a third of the lines of code. A thousand lines of clojure is a significant refactor or a big feature. A thousand lines of java is wednesday.

For me, clojure provides a simple-to-use API, high-level functional abstractions, an instantaneous feedback loop, access to a battle-tested JVM ecosystem, and more than fast enough performance. This is its killer combination, in my opinion. The immutable-by-default data structures are also an underappreciated boon for writing multi-threaded code without breaking a sweat.