Since you mention Apple/iTunes: I'd argue that it's the rule-proving exception. Yes, Apple's managed to implement micropayments with a music service based on 1) bog uniform pricing (99¢ no matter what — though that's changed since, no?), and for a fairly standard product for which previews and sampling are readily available in many cases — that is, the buyer has a very good idea of what they're buying in most cases.

And yet... there are numerous alternatives which aren't Apple: streaming music services (a bundled, non-micropayments model, either pre-paid or adverts supported), YouTube (adverts). Frankly, I've largely gotten out of the music-buying habit, though I'll pick up a CD occasionally at a show.

Your points on statement review largely make my point: if the idea of micropayments is to make people rational consumers of content, then if they're failing to review and assess their purchase habits, they simply aren't rational consumers. Which is to say, the premise of micropayments is false.

For long distance, he specifically addresses the case: the cost of attributing billing costs was itself a huge portion of the cost of service itself. By moving to flat pricing you can at once reduce costs and reduce customer anxiety over service use. I've been on flat-fee pay-as-you-go comms plans for years now. For what I'm paying, it literally isn't worth the telco's time to compute costs.

The kitty payment method is pretty much precisely how music broadcast and public performance (think bars, restaurants, stores) payments work. You've got a few licensing agencies (ASCAP, Harry Fox), playtime measurement (logs from radio stations and the services providing streams to retail establishments), and artists are cut a check based on plays.

Various checks and balances keep everything reasonably honest. Performance licenses are held by establishments and not performers -- it's the nightclub owner, not the band, who's on the hook for the fee. That greatly simplifies logistics -- on the spectrum of unreliable characters, bar owners rate higher than drummers, or even front-men. Shenanigans by the licensing agencies can be pursued by class-actions among musicians (not to say they can't or don't get screwed, but there are some checks). And the end consumer of the music (bar / nightclub / restaurant / store patron) doesn't worry about any of this at all.

The whole "rewarding quality" is something to consider, though I'll note that Apple dispensed with this entirely at least initially: everything cost the same amount. I can see (and have made) arguments to why this shouldn't be the case (high-quality scientific research or investigative journalism strikes me as more worthwhile than algorithmically generated tone patterns). And I'm not pretending to have a solution fully worked out. But I'm almost certain it lies in the direction of aggregated, not disaggregated, payments. Broadband tax. Syndication fee. General funds tax. Patronage to creators. Something like that.

As for Wikipedia: it follows patterns of collaborative work which date back centuries (review some of the early history of dictionaries and encyclopedias).

Bitcoin's got numerous problems, of which scaling is one. Trust another.

PKI's roots trace back to at least 1874 and William Stanley Jevons, who's just become even more interesting in my estimation. The primary limitation, aside from successful algorithms, was cheap and ubiquitous computing. As that came online, first for institutions and governments, later for individuals.

I'm not aware of any significant discussion that PKI was impossible. One-way functions have been known for centuries. Rivest, Shamir, and Adleman's work postdated national security implementations of PKI by British GCHQ by only three years.

Discussion of absolutes is risky, but there are a few.

I challenge you to exceed 300,000 km/s.

Others similarly exist in various fields, including social and economic ones. Part of the basis for my own statements is Gresham's Law, which I'm coming to view as a fundamental and principle limitation for economics. Others would include the Law of Diminishing Returns, and variations of the maximum power principle (Darwin-Lotke energy law, White's Law).