This can work in a lot of industries - I am skeptical fast food is one of them. Switching costs are low, alternates are plentiful, and collecting information (reviewing deals/prices across companies) is relatively easy.

If McDonald's enshittifies its deals while continuing to raise prices, it's way too easy for loyal customers to go elsewhere. I'm saying this as a huge fan and extremely loyal customer of McDonald's for decades... they are at serious risk of losing people like me. As I stated, I've gone from 15-20 visits to 1 since last June/July, whenever they made the big change.