Varies by actual DB but: with this architecture, if the DBs are NoSQL then you didn't lose as much by splitting up the databases, but if they were SQL then among other things you lose transactions across those DBs (or now need costly distributed transactions), effectively making the collective SQL system behave more like a NoSQL DB.
Varies by actual DB but: with this architecture, if the DBs are NoSQL then you didn't lose as much by splitting up the databases, but if they were SQL then among other things you lose transactions across those DBs (or now need costly distributed transactions), effectively making the collective SQL system behave more like a NoSQL DB.