They had a revenue of $416 billion in 2025.

That would be like you buying something at the dollar store.

If Apple doubled their Mac revenue, the financial benefit of Linux would remain the same. That means it would then be effectively half as important for their business, but the operational challenges and risks remain the same.

At some point the ongoing maintenance and support as well as coordination and organizational distraction mean it wouldn't get approved if internal engineers offered to start it off for free.