[notahacker]

That might be the theory. In practice, even if I click the "only on Deliveroo" option, I'm looking at a list of restaurants that spend a fortune on premises and their own marketing campaigns (including at chain level); they're selling on Deliveroo not because they don't already have high marketing and premises costs (to pass on) but because they're really not expecting enough takeaway orders to justify running their own delivery operation.