If it isn’t real then they should end letting people post fake tips, paying in advance isn’t a tip anyway, it is telling someone what you will pay them to deliver your package to you, like the USPS or Fed-Ex.
Exactly. But hear me out....
The pre-tip feature is a way for customers to induce drivers to accept that order for pickup. Let's say someone is craving chips and guacamole from Chipotle, and it is a 20 minute drive, 8 miles. Now the driving fee is solely distance based, and the suggested tip on a $5 order may be 1$. So the total amount a driver would normally be offered for this order might be calculated at $4.00. And no driver is really going to want to accept that order.
So, the customer has an opportunity to add an additional incentive up front by promising a $6 tip. The pickup is now for $10, and a driver may well accept that. What too often happens is that the driver accepts the offer expecting $10, but after the pickup, the customer has the ability to reduce the tip - supposed to be just for bad service but some customers abuse this - and zeros it out. So now, the pickup that was supposed to pay $10 now only pays $4, and the scummy customer is laughing because they pocketed the promised tip themselves.
That's a bad system. However, the customer having the chance to offer that "pre-tip" is a good idea because it essentially is freedom of contract. Suppose you've ordered $150 worth of food from a decent restaurant, and don't want it getting cold waiting for a driver to accept the order. So, you offer an extra $20 for the order to be picked up, which will happen very quickly once it gets posted for drivers. You get your food dast, driver may have made $40 total, and it's a win-win.
Alternatively, you could just not call it a "tip" anymore and make it irrevocable, but that would screw the drive in terms of taxes and also reward bad service. That's why simply posting the percentage of times a given customer (and yo don't know their nes or anything) paid the promised pre-tip would be a fair solution.