While they are all long lived, they have had incumbents come in and eat (*some) of their lunch.
MSFT missed the boat on mobile and have given up from a HW standpoint. Apple missed the boat on the cloud (tbd if they can catch up). Google missed the boat on social.
I would rather say "screwed up" rather than "missed the boat".
Microsoft never was a hardware company but their software powered many pre-iPhone smartphones. If you are into Android hacking, you probably know about xda-developers. It got its name from the O2 XDA brand, a brand of Windows Mobile early smartphones. They were on the boat, they just couldn't keep up. When tablets became a thing, they had a second chance, they tried to take it, but failed.
Google had Orkut before Facebook even existed, and every few years, they try a new social thing, and they invariably fail.
As for Apple, they didn't really miss out on the cloud. Apple has cloud services... for Apple device users. It is an exclusive service they offer to people who buy their overpriced devices, and it seems to work well for them.
The failures, I think, are just a matter of corporate culture. What helps them one way handicaps them in another. Microsoft focus on business hinders their ability to consider consumer-focused mobile devices. Google machine-centric doesn't help with the human element of social interactions. And Apple focus on hardware limits the availability of their software.
Microsoft didn't recover from the post-dot-com-bust slump until 2012(!), but it's done amazingly well since. It's a magical tail of recovery and/or proof that having a nice monopo gives you an extra long lease on life.
MSFT missed the boat on mobile and have given up from a HW standpoint. Apple missed the boat on the cloud (tbd if they can catch up). Google missed the boat on social.