Why do grocery stores bother with in-store coupons?

Perhaps, I just don’t get the idea behind it or how coupons work. I understand

However my local H-E-B grocery store still recommends that I rip off a yellow piece of paper from an aluminium ring and give it to the always friendly cashier before I can save 55 cents on my package of bacon. Why don’t you lower the price? Why not just offer the lower price automatically with an HEB app? Encouraging people that would save money if they signed up and used the app that automatically applied their coupons when they used their Application which could give display ads of deals, save time applying coupons, and free up a ton of man hours printing and stocking those yellow coupons. You could even provide analytics of how much overtime the customer was saving by shopping at HEB. You would even be able to apply receipts to accounts and save by not having to print receipts. Saving a ton of time and resources and progressing to the Future.