That has always been one of Clojure's main strengths (async & concurrency). With the new JVM VirtualThreads, things are looking better than ever.

The transition of core.async specifically to VirtualThreads is still WIP as far as I understand, but with minimal tweaks, 90% of the benefits are already there, even with the current latest version.

Virtual thread support in core.async is imminent, should land any day now.