From my own experience, among projects currently in development, these services are pretty much widely adopted. Very few people host their own databases, and I

From my own experience, among projects currently in development, these services are pretty much widely adopted. Very few people host their own databases, and I will usually advise against it unless there are unusual security reasons (e.g. you cannot trust Amazon or the NSA). Many old projects, due to costing some amount of time/labor to switch, will likely never move to these database services.