What are you known for? What words come to mind when people think of you? Are you known for a vision or known for a product?
McDonalds has an interesting problem. They're getting crunched between rising beef prices, a more health conscious customer base, and even environmental and PR concerns as beef production is considered by many a major driver of global warming?
So the cost of making burgers is going up. Demand for burgers is going down, and could even fall of a cliff in coming decades.
But McDonalds is about more than burgers. It's about convenience, affordability, and fun. Watch their ads. Notice how the focus is always on smiles, happiness and people. The food plays a supporting role.
McDonald's can add chicken wraps and salads to the menu quite successfully. Hamburgers will stay central to the menu for a good while, I'm sure. But we can also see a lot of possibility in other directions.
McDonald's brand allows them a lot of flexibility. The focus is on 'fast, cheap, convenient food served in an environment full of smiles'. That focus can include burgers, or chicken wraps, or even kale and tofu. It won't be easy, for sure. But you can see the possibility of a pivot into healthier futures. I suspect they're regularly discussing options like this.
Burger King, on the other hand, is going to have a tough time changing. Their vision, to be the "king of burgers", is tied to the product. And while I agree their burgers are much better than McDonald's, they are pretty much chained to that anchor. If demand for burgers collapses, Burger King will too.
McDonald's has cleverly built the foundation of their vision on giving customers fun, fast, and convenient food. Creating a personal outside the value of your actual product sounds like the completely wrong thing, but it's allowed them to adapt.
If demand for all your products were gone tomorrow, what instilled value would you still be able to offer the world?