There are lots of things to consider when introducing a new payment system for RSS. Companies like Uber, Lyft and Taxi Magic should start thinking of ways how to engage people who have no credit cards or Internet access (or both). As mentioned in my blog, the number of people in this category is significant and it will be a good business opportunity for RSS companies if they can offer services to none credit card users and people who have no internet access.
I agree that cash payments may be more risky and inconvenient but there could be other payment channels that can be explored i.e. bank-to-bank transfers, Alipay, pre booking over the counter etc. I think the challenge for RSS companies is providing the same level of service (features they offer in their online application) to non-credit card / Internet users.