> it's not exactly clear to me what happened to cause the lower price (I would assume 'no fees' just means the price would be the same as at the restaurant, not lower)
I believe I read elsewhere that DoorDash would (in addition to not charging fees) underprice items during their "restaurant acquisition period" as an additional way to inflate sales numbers, so when they go to the restaurant to negotiate a deal, they can say "in the past month we delivered 500 of your pizzas to customers! With your $24 price, that's $12,000!" ... while they conveniently hide that DD themselves only charged $16 per pie, and it doesn't take an economist to understand that more people will buy a product if you reduce its price by a third. Or, more relevantly, fewer people will buy a product if you "increase" its price by 50%.
I'm on the fence on this, I completely agree with your analysis but I would note that they originally thought DoorDash just scraped their website incorrectly for the prices. Even with the update at the end it's not exactly clear to me what happened to cause the lower price (I would assume 'no fees' just means the price would be the same as at the restaurant, not lower). That said, whether it's unethical to abuse a mistake made by such a company is up to you, I'm certainly not losing any sleep over it :D