If the debt is never called, yes, that is true. However, most companies don't get that luxury. For regular poor people, eventually those who control those companies need to call the debt to get the food, shelter, etc. they need to live and, when possible, things like entertainment, vacations, etc. to make life enjoyable. However, once you become rich, you transcend beyond that — where you cannot ever begin to call all the debt you've accumulated. It's a uniquely rich experience to be able to sit on billions of dollars worth of debt and not think twice about those who owe something.
> If Apple had made their products cheaper so that they just broke even, according to you, they would not have given away anything for free
Exactly. In that scenario both the buyer and seller exchange an equal amount of value. No debt lingers to be paid (or never paid, as the case may be) in the future. But Apple wants more. They want you to promise them something else in some hypothetical future.
Not because they think you, average Joe who cannot think of anything to offer the world beyond simple labor, will actually ever come up with some magical thing they want to buy. But because they know that the idea of holding debt gives them social standing; prestige. They aren't taking your promise expecting something real in return — hence why the debt simply accumulates — they are taking your promise because having that promise on paper offers them value.
And in some robot/AI future where humans no longer can even offer labor as something of marginal value, holding debt will still offer social standing and prestige all the same. Therefore there is no reason why these companies wouldn't continue to sell products to humans for fictional future promises, just like they already are.