Sure, but you could always do that and be delivery-only without paying anyone. I think the service you're getting here is primarily the exposure of being on a popular platform.
So do it? I really don't see the problem. I get that Deliveroo puts you on their platform even if you don't agree (the apps where I live don't do this), but if that's the case the restaurant is still getting the full price for selling their food. The customer pays the extra 20%.
Which means they might order less food than they would have with lower prices. Or that they might decide it's too expensive, and order from another restaurant.
Yeah, there should be a regulation that lets restaurants opt-out, or enforces price transparency on the delivery company's app (must show both original price from the restaurant in addition to final price).
> Delivery companies are free to buy and resell product from restaurants and add their own markup.
Which is fine. I think the problem is that they are representing themselves as if they are the restaurant, not a reseller. Customers might go to the website the delivery company setup (restaurant-name-location.com instead of restaurant-name.com or whatever their pattern is) instead of the restaurant's website, see the high prices, and decide to try a cheaper place.
A customer buys from a restaurant on a platform, gets the food served cold, and instead of blaming the platform for bad coordination, blames the restaurant for serving it cold, or blames the driver for serving it cold, often by publicly posting on the same platform which screwed their order, hence deflecting blame from the platform onto the driver or the restaurant.
> Last touch of any transaction gets all the blame.
That's exactly my point - and your last touch is the Deliveroo worker. So take it up with them. They can then take it up with the restaurant if it was the restaurant's fault, but that's their job as the reseller.
That and them handling the order process.