How can a serious company using a relational database get by without paying for database expertise in some way or another?
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".
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.
IMHO Hetzner is far above AWS/GC/Azure in price and simplicity.
The only drawback I see in Hetzner is that they don't have a lot of data centers with a relevant geographic dispersion, but that's only relevant for a Unicorn-level scale, or applications that require TP99.99 latency in the lower-end of the double-digit scale uniformly throughout the globe.
It works well, and the pricing is very appealing. But it's not even remotely in the same league as AWS/GC/Azure.
All you get is DNS, private networks, load balancers VMs and storage volumes. That's it.
Sure, you can self-host Kubernetes, and they even have a CSI driver for mounting volumes and an official Terraform provider. Which is great.
But you miss out on the incredibly rich service offerings you get from the others.
It's a great start though, and I hope they keep expanding their offerings.