From my personal experience of working on it, it is becoming simpler every month. So from a infrastructure standpoint, it is going to be much simpler than vSphere or Openstack. This is a no-brainer.

Now, do everyone need to run their applications on Kubernetes? Say, I invested millions $$ into Kubernetes, but the very business applications that my team built were proven to be not worthy. Then I see competition happily using same old VM, lambda, api gateways, but much improved operations (logging, ML, automation). I think what is going to decide the widespread success will be the adoption of applications that run on Kubernetes. It will be 3-5 years until we know. Right now it is a honeymoon phase and let us enjoy and ride the wave.