Why do you need page transitions for articles at all? The only reason I can think of is for more ad displays. Ok, if you have, say, a long manual with multiple chapters that would be several hundred pages when printed it can be nice to break it up, but that's probably not what you meant.

> photo galleries - after 25 years, why isn't there a standard user experience for viewing photos related to articles?

Because there's no one size fits all solution. Look into magazines, newspapers, etc. After a few centuries there is still no standard. Grouped, with captions, position, size, etc.

> why do we need to write CSS to create a basic readable document in the first place

You don't. Browsers can display semantic markup just fine without any CSS. The fact that you even ask this question is why you write CSS, because different people in different times expect different styling, and they don't think the default style is pretty. I agree that the default styles could be improved though after 20 years, but that could lead to breakage of current CSS styles, and why risk that if everybody uses CSS anyway?

And the fact that I wrote this comment is just another reason why you have to write CSS: because not everybody agrees on how the web should look.

This is only true if you constrain the "web" to mean the Tim Berners-Lee document-centric HTML and its http hyperlinks.

The "web" also means the whole internet stack, TCPIP, DNS routing, etc. In that case, the web is a foundational tool for anything that connects people or Internet Of Things. To say the "web works best as a document platform" is like saying "the electricity grid works best as a lightbulb platform." We've gotten past the historical motivations of a interconnected electricity and have done other things with it.

Do some "native" apps do nothing more than what a 100% static HTML could do? Yes, abuse of a Javascript widget framework does happen. However, the bad examples don't mean the "web" should be held back by the original visions of HTML or Hypercard. The Google maps app is not traditional HTML+CSS.

EDIT: The replies misunderstand my position. I'm not trying to redefine the traditional technical meaning of "web" and make you like it. I'm attempting to explain that "the web" has evolved and what it now means to the world out there. (E.g. see non-document usages like Dropbox, google maps, online Sudoku games, etc.)

By contrast, corporations can more easily make these sort of decisions – by fiat – which is why native app frameworks are more "opinionated" / make more design decisions for you out of the box.

This topic is as much the story of two historical forms: the operating system GUI and the World Wide Web hypertext project as it is about two organizational forms: hierarchical corporations and decentralized design-by-committee non-profits / multiple competing corporations.

As far as I am concerned those things only exist to inflate ad views, they have negative usability impact. I don't really see why a long document should be broken up in pages to be readable.

> The same with photo galleries - after 25 years, why isn't there a standard user experience for viewing photos related to articles?

There is one: right click → open in new tab. It work very well, much better than the jquery kludges that people come up with.

> In fact, why do we need to write CSS to create a basic readable document in the first place? Why doesn't HTML/CSS default to a high-end and legible reader experience out-of-the-box for basic text?

I find plain un-styled HTML to be much more readable than the tiny light gray webfont on white background that designers usually settle for these days.

I recall when I used Opera, you could scroll down, hit space, and it would go to the next page as long as the website provided that information (forum softwares often do.)