Tons of organizations run vault and consul as part of their k8s ecosystem so they don't directly compete. The vault CSI driver might be the single most installed CSI driver across all the orgs I've worked for
If you are running Nomad as your orchestrator, because of the tight integrations you are almost certainly running vault for secrets and consul for service discovery/service mesh. The ecosystem of the three is the competitor to K8s.
s/ someone who runs both ecosystems at scale.