Using coupons is an illusion.
Manufacturers and stores add in to the product prices the cost of using the discount of the coupons.
For example, if they figure 10 percent of all customers will use the coupons, they add a cent or two in compensation.
Those who don't use the coupon, are paying for 'your' savings.
Coupons are just another form of advertising and an attempt to get your brand loyalty.
Obviously coupons are factored into prices etc. but there is no reason not to use them. If a coupon makes something you were going to buy cheaper, thats a saving, not an illusion.
You sound like you dont use coupons on some strange principal.