I'm not sure whether you are asking whether people use Database-as-a-service instead of installing the DB themselves or whether you are asking about on-premise

I'm not sure whether you are asking whether people use Database-as-a-service instead of installing the DB themselves or whether you are asking about on-premise vs cloud Infrastructure-as-a-service. As many have noted, DaaS is very convenient but not always completely flexible with configuration and the pricing is not comparable since there is usually a minimum price even if you only want 1 table with 10 rows so it won't scale in the same way. For all of my home and work projects, we have servers hosted on the cloud to get better internet bandwidth and we install and run our own SQL Server and MySQL instances. A bare Vm is pretty cheap on the cloud and installing databases is fairly easy, although I have never personally setup clustering or failover in MySQL or SQL Server, I think that is quite involved.