Databases are there to share data and provide transactional guarantees and even locking. Your data often must be tightly coupled like this, and most databases designed with this in mind and provide benefits when doing so. It doesn't mean your apps need to be, and there are still plenty of benefits in deployment and operations to be had with microservices. Silo the data when it makes sense, but force the issue you end up with a different problem trying to reimplement the benefits of a database in the app layer or with a fault tolerant, guaranteed delivery messaging system (itself a database under the hood).