Even with past object lessons like AOL, Yahoo!, Blackberry and MySpace, people still think that whatever tech is dominant now, will be dominant forever.
@kyle I think you are leaving out the first and second largest companies in the world, both of which were dominant both back then and now (Apple and Microsoft). The fallen companies you listed did not monetize, and integrate themselves into, the daily life of every individual in the country. Would I be surprised if Snapchat or Discord gets bought out or sold in the near future? No. Google or Amazon? They are here to stay until antitrust comes knocking.