And the restaurant can say “no.”
If I were a restaurateur and caught a glimpse of a Doordash driver in my finest establishment, the first thing I would do is put together a simple online order form and start advertising it in every order. If you just disappear from the app one day, your customers trying to reorder would probably go somewhere else – but if they know they can order on your site instead, they probably will (if your food is good enough and your ordering experience is top-notch, or vice versa).