One issue with Redis as a queue backend seems to be that persistence is quite expensive, at least for managed Redis instances. Using PG seems like it could be much cheaper, especially if you already have an instance with room to spare.

I thought it was an interesting article, and I'd love to hear more from people using PG for queues in production (my intuition would say you'd get a lot of table bloat and/or vacuum latency, but I haven't tested it myself), but when it comes to the conclusion - "choosing boring technology should be one’s default choice" - I can't think of anything more boring (in a good sense, mostly) than Sidekiq + Redis for a Rails app.