It can go wrong. I had a horrible experience with StackGres. I read a lot of positive things about CloudNativePG though. I can see where people with startups are coming from not wanting to manage database plumbing so they can focus on real business tasks. I think that's fine as long as there is a path to self-host after some growth. I might do some event-sourcing myself so that databases are effectively materialized views easy to add and remove.

That article is good if you don't care about uptime or incident recovery time.

Yugabyte is the best open source postgres for HA.