Postmates and Uber Eats are here too. Can't really see why people would use Rappi. You also have a service called Cornershop for groceries so Rappi's competition here doesn't make it appealing.
Cornershop is groceries delivery made right. The person who picked your items is the same who delivers it to you, there's no dilution of responsibility. Wrong product? missing items? bread crushed under the milk? They will own up to it and fix it.
Previously we used HEB's own delivery service. One person picks your items, other packs them and yet another delivers it. When something is wrong no one owns up to it.