This is a common sentiment, but the security story isn’t so clear cut as that. Encrypted at rest really just means that if you yank the disk out of the server, an adversary can’t read it. But if it’s a system that is online serving a database and you gain access to the application reading from the database, encryption at rest doesn’t save you. It’s obvious the application server must be able to read the decrypted data. If an adversary breaches the application, they get the data.