Your dependencies might be tied to different JVM versions. Less likely but happened few times, especially during 8 to 9+ transition. You would've been stuck wit

Your dependencies might be tied to different JVM versions. Less likely but happened few times, especially during 8 to 9+ transition. You would've been stuck with your entire system on Java 8 for ages. Also JNI won't be isolated which occasionally might be a factor (more likely for stability). On the other hand one could make colocated multi-process services to work around this while avoiding all the other complexities of microservices.