> i suspect that the blog format discourages the latter.

I don't really see how the blog format makes this any worse than writing published essays did.

The foreword to "American Essays"[1] edited by Shaw is remarkably relevant and on-point for what I would consider the good parts of blogs and on-line writing. There aren't all that many that I am aware of that write consistently and well - apart from the odd article in The New Yorker, Greenspun, Spolsky, Graham as well as Norvig are a few that come to mind (and I'm reminded I've not really read anything by any of them lately).

Many of the blogs that are posted here on hn are good first drafts, that if the author found the time to put in about three to five times the effort, might be considered decent essays. I absolutely understand why people don't do that -- it is a lot of work, for little immediate reward. But I think that a lot of writers could do well to aspire to match Hemmingway or White, rather than just trudging out interesting first-drafts and sketched ideas.

I believe the greatest benefits to the authors, other than improving their writing skill, would probably be improving their thinking - the level of understanding needed to write simply and delightfully about a subject is significantly above the level needed to jot down a few ideas and join them into sentences by rote application of a few stylistic guidelines.

We should probably all aspire to write better than a well-trained neural network that takes a few keywords as input ;-)

[1] Unfortunately I only have the paperback, and can't find the time to transcribe it all. Should be available as a preview in the Kindle edition, I assume:
https://www.amazon.com/American-Essays-Charles-B-Shaw/dp/B00...

The volume appears to be oddly missing from Google books, I would think that has been scanned, but it appears not:
https://www.google.no/search?tbm=bks&hl=en&q=e+b+white+essay...

I also came across an old note on another essay collection, "Essays of E.B. White" - from his own foreword:

"The essayist is a self-liberated man, sustained by the childish belief that everything he thinks about, everything that happens to him, is of general interest. He is a fellow who thoroughly enjoys his work, just as people who take bird walks enjoy theirs. (...) Only a person who is congenitally self-centered has the effrontery and the stamina to write essays.

There are as many kinds of essays as there are human attitudes or poses (...). The essayist (...) selects his garb from an unusually extensive wardrobe: he can pull on any sort of shirt, be any sort of person, according to his mood or his subject matter -- philosopher, scold, jester, raconteur, confidant, pundit, devil's advocate, enthusiast. I like the essay, (...) but I am not fooled about the place of the essay in twentieth-century American letters -- it stands a short distance down the line. The essayist, unlike the novelist, the poet, and the playwright, must be content in his self-imposed role of second-class citizen. A writer who has his sights trained on the Nobel Prize or other earthly triumphs had best write a novel, a poem or a play, and leave the essayist to ramble about, content with living a free life and enjoying the satisfactions of a somewhat undisciplined existence. (...)

There is one thing the essayist cannot do, though -- he cannot indulge himself in deceit or in concealment, for he will be found out in no time. Desmond MacCarthy, in his introductory remarks to the 1928 E. P. Dutton & Company edition of Montaigne, observes that Montaigne "had the gift of a natural candour....". It is the basic ingredient. And even the essayist's escape from discipline is only a partial escape: the essay, although a relaxed form, imposes its own disciplines, raises its own problems, and these disciplines and problems soon become apparent and (we all hope) act as a deterrent to anyone wielding a pen merely because he entertains random thoughts or is in a happy or wandering mood.

I think some people find the essay the last resort of the egoist, a much too self-conscious and self-serving form for their taste; they feel that it is presumptuous of a writer to assume that his little excursions or his small observations will interest the reader. There is some justice in their complaint. I have always been aware that I am by nature self-absorbed and egoistical; to write of myself to the extent I have done indicates a too great attention to my own life, not enough to the lives of others. I have worn many shirts, and not all of them have been a good fit. But when I am discouraged or downcast I need only fling open the door of my closet, and there, hidden behind everything else hangs the mantle of Michel de Montaigne, smelling slightly of camphor."

-- E. B. White, 1977, in foreword to Essays of E. B. White

https://books.google.no/books?id=wkTusWRWdlQC&pg=PA4&dq=e+b+...

As a mental exercise, substitute "blog" and "blogger" for "essay" and "essayist" as appropriate...