The primary benefit I see with cash is that it's simply trivial to accept. A store owner, market stall holder, hawker, beggar - anyone can accept cash, trivial

The primary benefit I see with cash is that it's simply trivial to accept. A store owner, market stall holder, hawker, beggar - anyone can accept cash, trivially. You hold out your hand, someone gives you some coins, done. None of the other payment mechanisms are that simple. Generally at a minimum a lengthy sign up procedure would be required involving identification; accepting credit card payments is going to further require purchasing or owning physical hardware. Cryptocurrencies come close (no registration, authentication, etc and so on required), but they don't (yet?) have the market penetration required to function as cash does. I'd say this is reflected in the cost of cash-only establishments vs. non-cash-only. All of the cheap takeaway-style establishments are cash only for good reason - it's the only way to just transfer funds without associated baggage.