That doesn’t give you high availability; it doesn’t give you monitoring and alerting; it doesn’t give you hardware failure detection and replacement; it doesn’t solve access control or networking…
Managed databases are a lot more than apt install postgresql.
If you're doing it yourself, learn Ansible, you'll do it once and be set forever.
You do not need "managed" database services. A managed database is no different from apt install postgesql followed by a scheduled backup.
Genuinely no disrespect, but these statements really make it seem like you have limited experience building an HA scalable system. And no, you don't need to be Netflix or Amazon to build software at scale, or require high availability.
Backups with wall-g and recurring pg_dump are indeed trivial. (Modulo S3 outage taking so long that your WAL files fill up the disk and you corrupt the entire database.)
It's the HA part, especially with a high-volume DB that's challenging.
But that's the thing - if I have an ops guy who can cover this then sure it makes sense - but who does at an early stage ? As a semi competent dev I can setup a terraform infra and be relatively safe with RDS. I could maybe figure out how to do it on my own in some time - but I don't know what I don't know - and I don't want to do a weekend production DB outage debugging because I messed up the replication setup or something. Maybe I'm getting old but I just don't have the energy to deal with that :)
If you're doing it yourself, learn Ansible, you'll do it once and be set forever.
You do not need "managed" database services. A managed database is no different from apt install postgesql followed by a scheduled backup.
It genuinely is trivial, people seem to have this impression theres some sort of unique special sauce going on at AWS when there really isn't.