I wondered the same! FWIW I'm currently migrating from managed postgres to self-managed on hetzner with [autobase](https://autobase.tech/). Though of course for high availability it requires more than one server.
For comparison, I'm now using UpCloud which uses network-attached storage for all volumes and easily hits 10k IOPS (up to 100k with some tuning).
I certainly may have missed something while testing this so I'm happy if someone else wants to contribute and correct me if I'm wrong.