We discussed situation at Vox.io over a lunch a few days ago and one of my coworkers asked who's taking care of the Vox.io service now that most of its employees are gone. "Oh, I guess the service runs on auto-pilot" Andraž said with such a casual voice as if companies running by themselves and without any employees would be the most normal thing in the world. I don't know of any example yet, but with a bit of effort it would already be possible to build a company that could run by itself without any human intervention. All web services are already almost completely run automatically with computers doing all the work while humans take care only of marketing, sales, and (business, product, engineering) development. While I don't see computers autonomously taking over development yet, I can well imagine a company that has automated customer acquisition thru digital marketing APIs and has implemented self-serve sales and automatic billing that pays for the cost of running the service in the cloud.
Taking such a view at a modern company also makes it very clear that the essential role of 21st company is to automate everything so that humans can focus 100% on adapting to change.