The JVM and GC have a learning curve for the people implementing the database. But most users wouldn't get exposed to any of that. And if you manage it properly, things work fine. I've used Elasticsearch (and Opensearch) for many years. This is not really an issue these days. It was 10 years ago when JVM garbage collection was a lot less advanced than it is these days. These days, that stuff just works. I haven't had to tune GC for at least half a decade on the JVM. It's become a complete and utter non issue.

There are many valid reasons to pick other products but Elasticsearch is pretty good and fast at what it does. I've seen it ingest content at half a million documents per second. No stutters. Nothing. Just throw data at it and watch it keep up with that for an hour sustained (i.e. a bit over a billion documents). CPUs maxed out. This was about as fast as it went. We threw more data at it and it slowed down but it didn't die.

That data of course came from kafka being passed through a bunch of docker processes (Scala). All JVM based. Zero GC tuning needed. There was lots of other tuning we did. But the JVM wasn't a concern.