Unless something has changed and I'm out of date, I think a piece of context here is fly postgres isn't really a managed service offering. From what I've seen fly does try to message this, but I think it's still easy for some subset of customers to miss that they're deploying an OSS component, maybe deployed a non-HA setup and forgot, and it's not the same as buying a database as a service.

So hopefully as fly.io get's more popular, there will be some compelling managed offerings. I saw comments at one point from the neon CEO about a fly.io offering, but not sure if that went anywhere. I'm sure customers can also use crunchy, or other offerings.