I see it more like McDonald's can't produce burgers fast enough because of a meat shortage, but Burger King has their own supply chain that allows them to supply extra meat. McDonalds now needs to buy patties, possibly at a higher price than they usually pay, from BK just to be able to meet their burger demand.

Is BK in a bad position? They get to run their beef plant at 100% utilization regardless of how good they're doing at marketing hamburgers, and they can use that money to keep improving their hamburger quality or marketing.

That's a weird analogy and also not fitting at all.

Let's stay in the similar space and talk what it's really about:

Imagine google builds 2 data centers and sells the raw compute(not services!) to AWS so that AWS can sell their service on top.

What an embarrassement that would be.