There's quite a lot of legroom between a moderate amount of vertical integration where you attempt to own key parts of your supply chain and being a megacorporation which owns absolutely every piece of your stack, including towns for your employees.

I'm suggesting the optimum for human freedom, welfare and prosperity is achieved when striving closer to the former rather than the latter, not that companies should strive to depend on others as much as possible.

(Though my use of "minimal" in the original post might've been misleading.)