That's the problem with uber. With pizza the driver will remember you (we DO know who tips well or not) and the kindest thing the driver will do is make yours his last stop. With uber other than a bad rating we can't hurt the pax. We may be able to remember them but even if we don't pick them up another driver will.Sure it is, never forget that it is anything other than a gift. No one is ever obligated to tip. there are certain social norms around it but it is by no means a requirement.
Do you know where the custom to tip food servers and barbers came from? Those are the people that could kill you with poison or a slit to the neck if you were not a good tipping customer. Poison maybe not so relevant these days but hawking a lougie in my weekly pizza is still a possibility so i will keep tipping that guy.
Always be nice to those who handle your food. And if you're not, never go back.
BTW we pretty much know not to leave our DNA behind on your pizza now.