I've used Rappi here in Mexico and it's probably one of the worst delivery services I've used. Just seems like they overextended themselves by going in multiple directions without being quite efficient at them. Their website also often shows promotions that suddenly disappear when you try to click on the specific restaurant and you then have to plead your case to the customer support representative. Overall not a very good experience. Their delivery people often make mistakes with items too.
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.