As someone who has to use Elasticsearch as an only data store, yes.

Can you elaborate on which issue(s) you encountered? We are considering Elasticsearch at the moment for document storage and search, versus postgres.

FYI, you might want to check out ZomboDB[0], which integrates Postgres and ElasticSearch. It's open source[1] and, fwiw, the developer was helpful when I pinged him with some questions a while back (and is available for consulting services).

From the project's github page[1]:

ZomboDB brings powerful text-search and analytics features to Postgres by using Elasticsearch as an index type. Its comprehensive query language and SQL functions enable new and creative ways to query your relational data.

From a technical perspective, ZomboDB is a 100% native Postgres extension that implements Postgres' Index Access Method API. As a native Postgres index type, ZomboDB allows you to CREATE INDEX ... USING zombodb on your existing Postgres tables. At that point, ZomboDB takes over and fully manages the remote Elasticsearch index and guarantees transactionally-correct text-search query results.

[0] https://www.zombodb.com/

[1] https://github.com/zombodb/zombodb