Depends what you mean by "database driver", but what disqualifies XTDB or Datomic, both of which have use outside of Clojure yet are implemented entirely in Clojure with the exception of the Java wrappers so you can use them naturally within Java or Kotlin?
Even then, talking about "pure Clojure" is a non-starter because Clojure is not a self-hosted language (yes, Java is self-hosted if you consider Jikes RVM, a JVM implementation in pure Java). Even if Java ecosystem were to dwindle, people can rely on the JavaScript, .NET, or Dart ecosystems thanks to ClojureScript, ClojureCLR, and ClojureDart existing.
I use ClojureScript daily and am not really affected by what happens in Java land. With that said, I always welcome improvements to the JVM, because I actually like the Java ecosystem; it's the only one that doesn't make me split hairs...despite the dreaded module system.