The actual customer can afford a service from Evri that makes a percentage of their customers unhappy to a level that is only partially related to those people's unhappiness. This isn't rocket science. Remembering the identity of the real customer is a start, though.
Evri has a lot of customers, some of whom (e.g. Amazon) are in quasi-monopoly positions. In that situation, the happiness of Evri's recipients is not the most important factor.
The actual customer can afford a service from Evri that makes a percentage of their customers unhappy to a level that is only partially related to those people's unhappiness. This isn't rocket science. Remembering the identity of the real customer is a start, though.