No company is too big to fail, as our last Great Recession proved. If not for the government bailout of General Motors, many of the US cars we drive today might have been Imports. Financial institutions closed, and those that didn’t need a serious infusion of cash.
Survivors evolve, they change their methods or go bankrupt, or merge (get absorbed) with other companies. When the “Bell System” split up, competition among the baby bells forced every other bell to step up their game in order to compete....that was a good thing.
AT&T (SBC) is attempting to do this as their Warner Media attempt shows, too broaden their base of customers. Disney, as an example, owns ABC Television Group, ESPN, Inc, Lucas Film Ltd, Marvel Entertainment also trying to broaden their base, and no longer the theme park, or cartoons created decades ago.
IBM & Honeywell each own at least 5 other companies, like many other big corporations....evolve or die.