We are, it's serviceable, but its expensive to run and extremely difficult to debug or try to extend. Spinnaker was designed to solve a different problem (orchestrating deployments onto ec2) and its k8s functionality was retrofitted onto it, and it shows.

Yes, but not by choice. Spinnaker is definitely the equivalent of docker-swarm, at best. Okay in some aspects and the idea is there, but it’s clunky and doesn’t scale well with multiple applications and teams.