Tipping 'nudges' are now popping up on DoorDash. If you don't leave a gratuity, you'll hear about it.
(www.businessinsider.com)
Generally agree, but if you use an app that only exists because of tipping being expected like food devliery apps, then if you don't put down a tip then no one is going to pick up your order. All they will see is a terrible pay for an order.