AFAIK your calculation also isn't true. Deliveroo pays it drivers 7.5€/__hour__ + 1€/delivery (or something like that), so as long as they do enough deliveries/hour, that should work out. I'm still more concerned about the absurd marketing battle, but in my personal perception it slowed down quite a lot the last months in Berlin.
The following passage explains it better:
"The components of Deliveroo’s revenue come from users in the form of delivery fees at £2.50 and commission fees from restaurants. The commission they charge is generally 10% of the order, with the average order being around £30. Therefore a typical order will generate around £5.50 and within an hour Deliveroo can typically generate around £16.50 per driver."
Source: https://thebusinessoftech.wordpress.com/2016/05/08/deliveroo...
My startup was in this space (Not the UK though) -- if you have any questions feel free to drop me a line
really, the only innovation they are doing is the exploitation of labour laws.
The only upside I see is that they actually spend money from quantitative easing and market bubbles in the real economy. They're a symptom of a sick financial system and a sick economy.
This business model doesn't belong to companies, but free association of workers. They all (Über included) should be closed down, the sooner the better.