It should be noted that most Database supported by cloud providers are actually MySQL (compatible) database. While Amazon supports a managed Postgres Database a

It should be noted that most Database supported by cloud providers are actually MySQL (compatible) database. While Amazon supports a managed Postgres Database as well, I would bet that their own MySQL database – Amazon Aurora – works best because it integrated best into the AWS eco system. Same goes for Google, unlike Amazon, the only managed Database they offer is a MySQL database (called Cloud SQL). I'm not disagreeing with your arguments (quite the opposite in fact), but that might be an important point to use MySQL over Postgres.