Fast food assembly lines allowed them to deliver at scale better than regular restaurants, true. But lunch and dinner prices (as well as different/restricted menus) are practiced by both types for the same reason, economics. McDonald's franchisees hated having all day breakfasts even though corporate insisted it brought in more people and that only reverted when Covid came along. My local McDonalds has certain items that are only available during prime business hours and not after a certain time. The prices have also been changing on at least a weekly basis if not more often as the price for my Saturday breakfast burrito habit keeps changing. Honestly - I can't see Wendy's or any other restaurant truly implementing "surge" pricing and this is just a euphemism for intra-day price changes to get on the buzzword bingo chart, with AI tossed in for good measure. How's it going to work with 20 people in line and person #9 gets his burger for $5 but person #10 gets charged $9 for theirs and poor person #20 gets charged $13!!