Uber already has "uber credit" system, for example promotions where you get $10 in your uber account. They could very trivially just add option, where you could

Uber already has "uber credit" system, for example promotions where you get $10 in your uber account. They could very trivially just add option, where you could add uber credit to your account with bitcoin (or any other push-only payment method, for example cash via coupons).