Picking the one company from that list I am most familiar with, AirBNB has been going since 2008. AirBNB are now the people acquiring and shutting down / changing other startups!
Sure, AirBnB certainly appears to have hit the scaling part. But I bet they're still trying to find new models and new markets. Hilton, Marriott, Starwood and others dominate the corporate travel market. Dropbox appears to be moving towards photo sharing on the consumer side and config/settings sharing on the tech side.
Startup, not startup. Probably irrelevant. I know that there's value in having companies who think like a startup as vendors. Procurement departments aren't structured to be allowed to think that way and I think that's bad for the companies they serve.
[0] http://steveblank.com/2010/01/25/whats-a-startup-first-princ...
[1] https://casetext.com/case/jacobellis-v-state-of-ohio/paragra...
How would AirBnB be any more of a startup than Google?