They’ve been driving people to use their app for years now. The menu prices isn’t what one pays if they use the app, since it has a constant stream of coupons and discounts that bring the list price down.
This walkthrough is just an example, open the app yourself and have a look, most of the deals are just an item or two away from being a thing people would actually order.
If I do eat McDonalds its usually just a burger + fry + drink usually around ~$6ish unless I'm ordering for others.
If everyone else refused to sell their data, we wouldn’t be in this position.