Comment by Sebb767
> Probably because actual time required to manage a db server is really unpredictable.
This, and also startups are quite heterogeneous. If you have an engineer on your team with experience in hosting their own servers (or at least a homelab-person), setting up that service with sufficient resiliency for your average startup will be done within one relaxed afternoon. If your team consists of designers and engineers who hardly ever used a command line, setting up a shaky version of the same thing will cost you days - and so will any issue that comes up.
Its a skillset that is out of favour at the moment as well but having someone who has done serverops and devops and can develop as well is a bit of a money saver generally because they open up possibilities that don't exist otherwise. I think its a skillset that no one really hired for past about 2010 when cloud was mostly taking off and got replaced with cloud engineers or pure devops or ops people but there used to be people with this mixed skillset in most teams.