I think there is some misconception on how CQRS works, its not mainly only for separating two data stores based on database Master-Replicas structure. Instead it may be a two different kind of database. And the point is "data" that stored in write-db should be simplified by an event handler and store to read-db so that "Query" can just do simple logic query from read-db that result much more efficient and higher performance. Unless "Query" required to perform complex queries (LEFT JOIN, INNER JOIN, etc..). That's why only complex business logic benefits from this pattern.