I feel like one of the problems with using Postgres as a queue is that it’s hard to get started. There’s a lot you need to know. Getting started with something like Pub/Sun on GCP is much easier for many developers.
I’ve experimented with making this easier via libraries that provide high-level APIs for using Postgres as a queue and manage the schemas, listen/notify, etc for you: https://github.com/adriangb/pgjobq