There was recently a news segment on TV where they spoke about apps which let the delivery workers see the tip and choose what orders to deliver. I'll start with my opinion that overall I think there are way too many deliveries and it's bad thing. Our roads/streets are being congested with excess traffic, and many of the workers are unsafe. Not just running red lights and endangering pedestrians, but the vastly increased risks for battery fires. It astonishes me that all these ultra health conscious individuals can't walk a little bit to pick stuff up.
But this last addition rubs me the wrong way. It's like holding your dinner hostage. Of course you should tip, but now the apps are telling you that if you don't overtip (as opposed to them paying their workers a decent wage) you may never get your order even though they have taken it and charged you for it. This also divorces the tip from actual service because you must make the decision on how much to tip before service is rendered.
Personally if they got rid of all the deliveries I would be perfectly happy.