One thing I realized working for a huge company and comparing that with my time at their much smaller competitor was that organizations in huge companies become hyperspecialized. This is great during the good times, because everyone is able to squeeze out that last 5% of performance (or whatever other metric they're optimizing for), and this combined effort allows them to keep their lead over the competitor.
But it's terrible during bad times because of the overstaffing. And firing people just makes things worse because the company loses important parts of its organizational memory. Because of the hyperspecialization, no single person/organization knows how to do all the things that need to be done to get the product out the door. And if you fire 10% of your workforce, you're going to forget 10% of the stuff you needed to know to build your products. In fact, you probably lose much more than 10% because people who are actually good see the writing on the wall and leave, taking a disproportional amount of the organizational knowhow with them.
I feel like these companies get caught in a death spiral. They can't do things the old way because they don't know how to any more, and they can't do it the way their competitors are doing it either because they never knew how to do that! So they just flounder along for many years slowly becoming less and less relevant. They solution is to luck into a completely different business model that somehow ends up working a la IBM in the 90s. But how realistic is that?