Maybe it takes an upstart to displace an incumbent rather than the incumbent reinventing itself. So for example you have Amazon vs Wal*Mart, Tesla vs GM... Now, some incumbets do have enough time to reconfigure (as WalMart is trying).
On the other hand... maybe corporations are better corporate citizens than we give them credit for (i.e. not everyone is a "Chainsaw" Al Dunlap. who want to shed workers as quickly as possible. Maybe some actually want to keep people employed as long as they can.