I don't disagree that there is a layer of complexity that can come with elastic depending on your configuration. If you would like, you could log a feature request to have the search libraries that you mentioned reviewed for inclusion into future iterations of FusionAuth. I took a look and they seemed very interesting; I appreciate you mentioning it.
In the meantime, if you haven't yet, you can check out the container repo and its search section. There are some pre-configured search settings to be found there.
https://github.com/FusionAuth/fusionauth-containers/tree/master/kubernetes/services.
We also have a helm repo that has been very active.
https://github.com/FusionAuth/charts
Also, I assume you are running a container orchestration service like K8's but if you are using just docker, then you can run this command and have elastic up and running within a single docker container (related link)
curl -o docker-compose.yml https://raw.githubusercontent.com/FusionAuth/fusionauth-containers/master/docker/fusionauth/docker-compose.yml && curl -o .env https://raw.githubusercontent.com/FusionAuth/fusionauth-containers/master/docker/fusionauth/.env && docker-compose upFinally, you can check out the installation guides for additional assistance and context.
https://fusionauth.io/docs/v1/tech/installation-guide/cluster/ https://fusionauth.io/docs/v1/tech/installation-guide/fusionauth-search/ https://fusionauth.io/docs/v1/tech/installation-guide/docker/ https://fusionauth.io/docs/v1/tech/installation-guide/server-layout/ES does give you the benefits of powerful queries that can be run from right within FusionAuth Admin UI or via the API. I have seen firsthand how this can really help you as your Monthly Active Users projects upwards and you have more data to sort and consume.
I hope this helps!
Thanks,
Josh