Should a restaurant leave the delivery platforms?

For most operators, no — the platforms bring reach and incremental revenue that dine-in alone cannot. The honest position is deliberate volume: know your true contribution per delivery order, price and build the delivery menu for that reality, and move what repeat demand you can onto channels you own. Delivery run with open eyes is an asset; delivery run blind is a leak a blended P&L cannot show you.

From Five Nights to a Tighter Restaurant P&L: Food Cost, Labour, Rent, the Platform's Cut and the Weekly Read — the full reading, with the method behind this answer.