Databases and search engines have different engineering priorities, and data integrity is not a top tier priority for search engine developers because a search engine is assumed not to be the primary data store. Search engines are designed to build an index which augments a data store and which can be regenerated when needed.

Anyone in engineering who recommends using a search engine as a primary data store is taking on risk of data loss for their organization that most non-engineering people do not understand.

In one org I worked for, we put the search engine in front of the database for retrieval, but we also made sure that the data was going to Postgres.