Thanks for the explanation. I had the wrong idea that it could be due to, for example, if A->B belonged to a different provider than B->C, providers not reaching an agreement on what % to take each, for the journey from A->C - hence increasing the overall cost for covering demands from both.
I feel you. Unfortunately, I don't think GDPR will be of much help on that case. A fine of up to 1% of they're revenue will hardly make a dent - it's just another tax. Misbehaviour will be still worth it.
Actually GDPR is of great help to them, by putting smaller competitors away from using similar techniques. For those, a 1% revenue is a lot.
In the UK, JustEat takes 30% of the order, same as UberEats, with 0 liability - if something goes wrong with the order, including problems with delivery time, driver taking a nibble, the restaurant just doesn't get paid. Deliveroo is a bit greedier and takes 35%.
It's definitely not the lack of competition... it's just that the competition doesn't behave much better compared to them.
Funny now that you mention.. I've been doing less and less side projects since my life got 'invaded' by social media. I wonder if I'm suffering from a similar problem...