> That's a big difference to an anonymous-by-default cash-only network.

I haven't used it recently but in 2013-2014-2015 it was as an anonymous-by-default cash-only network. (edited original post to reflect it)

Overall I had zero problems, very nice experience, and I met interesting people

You used to be able not to use any of their payment services. Also identity verification processes that they offer/ed are/were not obligatory. So in many cases references were all people used to trust someone.

(I have been using the service for years)

They operated for years without accepting payments, the payment is a recent thing.

Their business model is to first expand to a territory by providing a simple connection between passengers and drivers. Then, when their user base is large enough, they introduce the payment system.

However, when I was using the service it was quite common to get the drivers number and contact them directly for the "next" time.

My point is that since the payments are a recent change, previously the rides were in fact completely anonymous.