You have a container that responds to HTPP requests sitting behind a load balancer, then you spawn a new container and tell load balancer to redirect calls to the new one. From the point of view of whoever is calling the load balancer you have hot swapping. You may even separate containers into logical groups and call it microservices architecture. Or you can define a process as something having qualified name and a mailbox and is sending messages to other processes.

Now reasonable people may disagree about what's wasteful, but the market seems to tolerate places where adding a checkbox to a form is a half a year process involving five different departments and the market can't be wrong.