Huh? Maybe I missed something, but...why should self-hosting a database server be hard or scary? Sure, you are then responsible for security backups, etc...but that's not really different in the cloud - if anything, the cloud makes it more complicated.

Well for the clickops folks who've built careers on the idea that 'systems administration is dead'... I imagine having to open a shell and install some stuff or modify a configuration file is quite scary.

Self-hosting a database server is not particularly hard or scary for an engineer.

Hiring and replacing engineers who can and want to manage database servers can be hard or scary for employers.

I'd say a managed dB, at minimum, should be handling upgrades and backups for you. If it doesn't, thats not a managed db, thats a self-service db. You're paying a premium to do the work yourself.