timdev2 sums up my original sentiment quite well. Is spinning up and maintaining a DB architecture doable? Of course... But there are so many complexities involved for real production that it would greatly slow us down.
If we had staff to dedicate directly to this then it wouldn't be an issue. But paying for a managed service that gives us production grade data access is a no-brainer for any non-trivial application we build.
I for one have always liked the simplicity of DO for hosting but I've never wanted to take on the full liability of self-rolling a DB server (and backups and replicas). So everything my company has I've put on heroku or azure. This has potential to be really significant as I'd wager there are a lot of folks in similar situations.
If we had staff to dedicate directly to this then it wouldn't be an issue. But paying for a managed service that gives us production grade data access is a no-brainer for any non-trivial application we build.