Direct reading effectively makes the data store an API, i.e. the API you provide is SQL SELECT over multiple tables instead of HTTP GET resource.
This pretty much freezes the database schema, the team owning it can no longer change it, because they don't know how the users use it. It also limits the possibilities to provide optimizations on the data (like caching).
This pretty much freezes the database schema, the team owning it can no longer change it, because they don't know how the users use it. It also limits the possibilities to provide optimizations on the data (like caching).