That's a very good question, and eventually it's safe to assume both Apple and Microsoft will collapse. The big differentiator though is their area of business. Both managed to become an integral part of work, personal life and business everywhere. They own both hardware and software, they have ecosystems. Any collapse would look very gradual, and would take perhaps over a decade if not two. Twitter, like Facebook and some others are on the other hand just one small tool, and people can shift from one to the other very easily. Their business model relying on ads and subscriptions is also very precarious. Collapses can be drawn out or abrupt. I think Elon's purchase will make this one an abrupt collapse as opposed to people just getting bored of Twitter.