At a certain point why would they sell anything other than services and products their eventual (actual) AGI/ASI builds in literally every market.

When opportunity cost isn't a thing anymore because it reaches every corner of the planet simultaneously faster and builds better than any human can.

There's no reason to let others build on top of AI, except if the AI determines that it needs capitalism to continue because it's paperclip goal is to maximize shareholder value.

most of the complexity in software isn't in the actual code