I think actually the middle way is the best. This is when you have a central platform that is operated by a Platform Team that App Teams can use to deploy their workloads -- but that the App Teams are expected to observe and monitor their own app to make sure it is healthy.
This way each individual App Team doesn't have to become a PhD at Kubernetes and the Platform Team (aka "Ops") doesn't have to become a PhD at 50 different apps.