The company I used to work for, used docker-compose to serve its SaaS product to 100+ clients. I wasn't part of that team, but it seemed to me they were quite happy with it.

Can second this: I've seen companies that wanted the benefits of containers but didn't need orchestration yet do just fine with Docker Compose in prod.

Of course, when orchestration became a necessity, almost everyone looked in the direction of Kubernetes, as opposed to something like Nomad or Swarm, probably due to its popularity.

tl;dr it wasn't before, but now it is.

It is true that there once was a disclaimer on the compose homepage that stated that the product was not recommended for production workloads.

Given that disclaimer no longer exists, along with the existence of [1], leads me to advocate using it in production.

[1] https://docs.docker.com/compose/production/