It doesn’t require that all. If anything, we are now seeing the opposite where top companies with considerable resources are remaining agile and innovative, effectively out-competing many new startups.

You're right... for now. We're seeing incredible concentration of wealth. Eventually they will become lazy and overly bureaucratic. Google, Apple, and Facebook in particular made their mark by dismissing customer service and by not addressing customer complaints, creating a culture of the "one true way". That culture + monopoly status will create (and is creating) a toxic miasma.

Apple has fairly good service if you show up at one of their stores with a broken device. Google and Facebook will also sometimes provide good service for actual paying customers, just not for users.

Also, the big technology corps are fighting their lack of internal innovation by buying smaller competitors. The executives are well aware of company lifecycle theory.

In technology especially, inertia is a liability. Not really surprising that most tech companies don't make it that long.

What is more surprising is that our attachment to institutions includes for-profit businesses. Really, we should, as customers/consumers, just go with the best service, but culturally we can't help but think that something is lost when an old, useless company goes away.

It's not required that successful businesses blow themselves up, but if they do make poor choices, they will suffer, and perhaps pay with their existence, for those choices.

It's not required. But just the same it should always be a what-if possibility. I'd say the poor choices come from a tunnel vision approach to those decisions.

Ultimately, in the context ans scope they are made, they are probably great decisions. However, reality is more far reaching.

Not always blow themselves up. Just continually reinvest. In their people, their products. The problem with our economic system is how short sighted corporations have become.