The McDonald’s coupons are always available under a menu in the app. You have to know to look for them though. Might be regional but in my area there’s always a 20% off your whole order coupon plus some others that can do even better.
Not to dispute your point that grocery stores also have a lot of coupons and promotions and it’s definitely cheaper than fast food (also grocery store food has even cheaper options like beans, rice, canned goods etc that may not be equivalent to a fast food meal but are vastly cheaper and may not take any real time or effort to prepare).
I see the 20% in my app, but it is for orders above $10 so may not work for a single sandwich order being discussed above. But for 2 people or more, it could be quite useful. Never used this and not a McD regular, but will remember this next time.
Not to dispute your point that grocery stores also have a lot of coupons and promotions and it’s definitely cheaper than fast food (also grocery store food has even cheaper options like beans, rice, canned goods etc that may not be equivalent to a fast food meal but are vastly cheaper and may not take any real time or effort to prepare).