There are some other possible reasons tho, like food actually not being as "commodity"-like as we think it is (like rides are)
The other hypothesis is that delivery is simply expensive. The driver has to drive to the pickup place, find parking, stand in line potentially for awhile, drive to the delivery, park again, walk to the delivery location to drop off the item. Most of those things an ordinary uber fare would not have to deal with.
Reminder that Adobe, Apple, Google, Intel, Intuit, Pixar, Lucasfilm and eBay all colluded to keep engineer compensation below market value[1].
[1] https://en.wikipedia.org/wiki/High-Tech_Employee_Antitrust_L...
A claim that all of these have formed a cartel requires strong evidence.
And 2 of those are potentially combining.
Looks like a split amongst 4 right now, as far as the big ones go. This doesn't include the smaller startups as well.
If you went to a VC with a model for a food service delivery taking less than 30% of the transaction, they'd more than likely pass. 30% is the bar that's been set, and your unit economics have to be as good or better than the existing players. They're not keen on investing in "just a cheaper version of something that already exists." -- If you're marketing yourself as "cheaper," it has to because some innovation has eliminated more cost out of the transaction than you have eliminated in net revenue.
We've been told that evil VCs subsidize service to run at below cost to drive competitors out of business. Uber is often accused of this. Why aren't we seeing that phenomenon here? And Uber is literally one of the competitors.