Docker Swarm is a hot mess.
- Swarm does not have namespaces, a swarm cannot be divided into multiple independent ones.
- Swarm CE does not have per-operator Auth
And
- k8s has more moving parts
- has more complicated config files
To me swarm is to k8s like nginx is to apache. The former is lean and easy to setup, the latter has all the bells and whistles for enterprisey, service provider scenarios.