QuestDB engineer here: We use jlink to create images for selected platforms. This means not even JRE is a dependency: You unpack a tarball and you are good to go. See: https://questdb.io/docs/get-started/binaries/
Keep in mind the JNI libs are platform specific. That means available platforms are a function of what the JRE runs on AND they have built the shared lib for (and bundled in to the jar)