For a multivendor business, your main customers are the End Customers who purchase from your application. If the power to cancel the order anytime is given to the Store Owner, you will start losing your business.
Let me remind you, on Foodomaa, you are the business owner, you are taking the risk and all the customers belongs to you. You are liable for any customer damage.
So if you give the option to the Store owner to cancel the order anytime, and if the customer has been waiting for their order for 30mins and then the Store owner cancels the order, your business will face issues with bad reviews and bad word of mouth.
Generally, if the Store owner needs to cancel the order (after it is accepted) they need to talk to the admin team (your staff) and then your team will take the decission of cancelling the order and processing the refund. (And then based on the damages, your team could send some wallet money to the customer as compensation for the time they wasted)
Obviously you are free to create a function on your own to cancel the orders from the Store owner dashboard even if it is accepted.