1997-2000 showed us that having a lot of money is no guarantee you'll build something that anyone wants to use (or at least, that they want to pay for).
Who said anything about any guarantees? Hopefully, we're all a little smarter and if all three companies each tried a few moonshots, we'd get a few really big advances.
https://news.ycombinator.com/item?id=8962872
Basically, Apple, Google, and Microsoft have so much money, they could take on a huge problem and "invent" the future.