This works right up until the inputs for Widget X and Widget Y require capital. Let's say Person A builds Widget X, and needs Input 1 to produce a Widget X. Pe

This works right up until the inputs for Widget X and Widget Y require capital. Let's say Person A builds Widget X, and needs Input 1 to produce a Widget X. Person B builds Widget Y and needs Input 2 to produce Widget Y. Person A uses their capital from their job to purchase Input 1 and produces Widget X. Person B uses their capital Input 2 and produces Y. Person A and B trade widgets and are happy. But now, as before, automation takes the jobs of Person A and Person B. They lose their jobs, but retain their desire for the opposite widget. Person A no longer has the resources to acquire Input 1, and Person B can no longer acquire Input 2. Neither X nor Y get produced, and both have their needs but are unsatisfied. There is no guarantee that new automation will continue to fulfill all the desires that were fulfilled previously.