When Postman refers to written word he refers mainly to books. The article mentions the increase of hours spent reading text as a result of texting, social media etc. This form of written word is actually close to Postman's concerns.
It's written word, but its metaphor is the same as the metaphor of mediums like TV.
I agree in part. The texting, social media, etc. has the same disjointed tone as the "now, this" attitude of television that Postman wrote about. However, he had a specific concern with images versus text (whatever kind of text) -- namely, that they pass too quickly for people to dwell upon and can never advance an argument in the way that writing can.
To be honest, I think this is a general weakness in Postman's work. He talks a bit about the difference between pre and post-telegram writing, but he lionizes all 18th century writing despite there being tons of different forms (pamphlets, books, novels) that don't have the same intellectual value imo.
A bank is not a central authority any more than large mining pools are central authorities. Or China (when it controlled enough BTC to double spend at will).
The banking system is vastly distributed. Trust is a giant network of accountants, central banks, regulators, investors, and lots more that help ensure there is no double spending. There are checks all throughout the system, ledgers, reports, audit trails, and, unlike BTC, when something is actually stolen, lots of protections and methods to claw back stolen money.
BTC can be double spent via majority control, so double spend protection is at best a statistical claim, just like real banking.
A large problem with Bitcoin is developers were unaware of modern (or even ancient) banking and money systems and have tried to reinvent simple money with all the same problems that mankind moved from millennia ago.
Then people unaware of the why of modern money systems think crypto solves an important problem that modern economies and users don't care about, while ignoring all the problems modern systems solved as if they don't exist.
And honestly, in all my life, I have never heard of anyone in the normal banking system double spend. So chalk one more up to the Bitcoin make believe event crowd. How many double spend events have you performed in your entire life via normal banking?
It's written word, but its metaphor is the same as the metaphor of mediums like TV.