As a subscriber, Careem would waive certain food delivery costs, you qualify for discounts and such.
I like how Careem shows you the savings you make in the app. I have seen certain apps in the UAE use that tactic which I think is effective.
A powerful customer acquisition tactic is Careem committing to reimbursing you if you did not get back the value in savings from the monthly subscription cost.
I am not worried about any losses to Careem for paying users back for reimbursement as Careem would easily make that money back by increasing loyalty. You order your food and rides and so on, from them instead of others. Loyalty is a big driver for long-term success. Amazon Prime brings in direct cash and loyalty with multiple repeat orders.