ES should be thought of as a json key value store and search engine. The json key value store is fully consistent and supports read after write semantics, refresh is needed for search api. In some cases it does make sense to treat it as a database provided the key value store semantics is enough.

I used it about 7 years ago. Text search was not that heavily used, but we utilized the keyword filter heavily. It's like having a database where you can throw any query at it and it would return a response in reasonable time, because you are just creating an index on all fields.