Is "modern devs" the modern "No true Scotsman"? Plenty of developers and organizations get by without managed databases. Although in "7-day sprints on loop forever" world of startups, any effort to require less knowledge to run the stack is probably welcome, hence it seems "most devs can't live without" for a lot of things, like managed databases, containerization and yadda yadda.

Having a managed database is the sweet spot for productivity/efficiency between maintaining a full time database administrator and having engineers learn how to do it themselves.

How can a serious company using a relational database get by without paying for database expertise in some way or another?

Yes, of course once the company reaches a certain scale you need specialized roles and/or software that you use, that makes sense.

But is "companies of scale" what "modern devs" refer to? What is a "serious" company?

There is a lots of parameters that goes into the choice of self-hosted DB / managed DB, not just if the devs are "modern", or the company is "serious".

> especially managed databases.

There are other companies, though, that have great cloud-managed DB offerings. Herzer (I'm not previously familiar with it so don't know if they already do this) would do better to just partner with one of these companies in a "marketplace" like arrangement.

I was extremely close to switching to Aiven-managed postgres until GCP finally supported point-in-time-recovery on postgres.