If you told McDonald's to double their number of McRibs produced next year that would be an incredible challenge to meet. They already sell enough that it affects the global pork market, it'd be insane for them to double their demand for pork. What about other supplies, would this result in a reduced burger demand? How can they ensure they can respond appropriately either way? They probably run near fridge/storage capacity, does increasing this mean they need to also increase storage at restaurants?

That's a 2X increase. Now do it again and a half for a 5x. Crazy to say there's a "scaling wall" that once you "pierce" it's easy to scale up. It's the opposite, McDonald's already knows how to supply and sell X McRibs a year, there's no company that's ever sold 5X those McRibs so they have to figure it out themselves.