Why do we need Uber in the first place? Where I live, there is an app that directly connects drivers to riders who pay cash, and nobody takes 30% fee fro mdriver's wages.
Where I'm from, it's the law that cabs should accept credit and debit, not only does it reduce tax fraud, but it also allow people like me to pay. Transaction fees are not that expensive, but believe me, companies that provide it to cabs drivers, does charge much more for it. Still it's less than 30%.
Again where I'm from, dispatcher does charge the drivers, and from what I read, it was not too far from 30% (which makes sense, they have to account for advertising, wage for dispatch by phone, and since Uber, for the development of a badly made app).
As a passenger, cash is far less convenient, and paying at the end of a ride is awkward, slow, and certain to change the dynamic with the driver.