It is up to restaurant management to decide, but, actually, no, this is not necessary.
For example, to perform delivery service you need to know some personal data to perform service, you just cannot provide it without knowing address or customer phone. So you don't need to ask for consent for that, as the information is necessary for you to comply with the contract for delivery that you have with your customers. Then you need to store data for a while – just to be able to provide answers in case of any complaints from your customer. Or even further, to provide better service at the repeat order and not to ask all his address info again. This is known as your "Legitimate Interest". You do not store data in vain, you do it for purpose, which is necessary for your business goals.