▪ Scalability

When we separate Read and Write databases, we can also scale these separate databases independently. Read databases follows denormalized data to perform complex join queries.

▪ If application is read-incentive application, we can scale read database more then write database.

▪ Query Performance

The read database includes denormalized data that reduce to comlex and long-running join queries. Complex business logic goes into the write database. Improves application performance for all aspects.

▪ Maintability and Flexibility

Flexibility of system that is better evolve over time and not affected to update commands and schema changes by separating read and write concerns into different databases.

▪ Better implemented if we physically separate the read and write databases

https://medium.com/design-microservices-architecture-with-patterns/cqrs-design-pattern-in-microservices-architectures-5d41e359768c