"Just be responsible with your credit cards" is an easy mantra to live by if you are financially privileged.
Citation needed
There always exists cash (except for internet transactions, of course).
Trying to make either a deposit or a withdrawal of "large sums" (> ~1K USD equivalent is my understanding) cash at a bank will get serious scrutiny and may even result in funds being seized or frozen.
Things have changed really fast, too. Just 2 years ago I don't recall ever being in a store which didn't accept cash.
And yet, all solutions other than cash are from private banks, which have no obligations to take you as a customer.
Unfortunately it seems like Sweden is far from alone in being on this trajectory, they're just a little bit ahead in this sense.
I do think that there's a case to be made for permissionlessly operated cryptocurrency on a public ledger here.
I note, however, that in your first paragraph you dismiss the "one true payment system", and in your second, you pretty much advocate credit cards as that one true system.
In the UK, credit cards are widely used but by no means universally owned.
In Berlin, quite a lot of places only take cash, and those which do take cards often only take debit. I don’t think I’ve even seen a single credit card advertised in the window of any high-street bank.
Our banking system here is backwards in many ways, but the rigamarole described here just doesn't happen. US companies are much better about separating people from their money efficiently, I guess.
Also, many of his gripes seem ridiculous. I don't know if the situation is different in Europe, but in the US I think pretty much everyone should have a credit card. You can use a secured card if you have bad credit, and most debit cards in the US can be swiped as a credit card. All of his non-existent problems seem like they could be fixed by getting a credit card. Credit cards also have better fraud protection, let you build credit, and usually have better rewards for consumers. There is virtually no difference in privacy benefits between credit and debit cards.