Accessibility is important, but it's not a reason for stopping progress. If it were, we never would have had computers at all. The solution there is more investment in making new technologies accessible, not preventing new approaches altogether.
That latter thing isn't really a benefit. Or if it is, it's satisfying your personal aesthetic sense. I too happen to think that past version of the future was awesome. But I also liked the future where we all used jetpacks to fly up to our long-haul zeppelins. That's no reason to ban airplanes.
You seem to be saying that web pages that are unusable without JavaScript or images represent "progress". For something to be "progress", it has to be both new and better than the old things. In fact, though, it's worse and not better, and it's not even new; it's a throwback to the days before the web, where you had to download special-purpose client software and learn a new UI to access each new online information resource, and bringing together information from different online resources was difficult.
To use your metaphor, this is not the future where air travel is cheap and ubiquitous; this is the future where the Concorde no longer flies, you must submit to a strip search to board an airline, and Meigs Field has been bulldozed.
I am saying that the people making more dynamic websites believe that what they are doing is better than ye olden dayes of the webbe. Sometimes they're wrong; sometimes they're not. When people make new things that they think are better than the old things, that's called progress.
I'm fascinated that you could work in tech and still manage to seize one small moment in technological time and declare it the peak of goodness. You realize, don't you that people do that with every moment of technological time?
I'm not denying that by your criteria the web was better then. I'm just saying that seizing upon the particular set of aesthetic criteria from the age when one is most impressionable and decrying all that comes after as worse has never been an effective way of changing things back.
You are attributing points of view to me which I not only do not hold, but which I find insulting that you could think I hold. I am disappointed that the level of discourse in this forum has fallen so far.
What sort of progress will be stopped by encouraging websites to present content as content instead of as an "app"? What specifically would you do to make websites that don't work without images or JavaScript more accessible, apart from making them work without images or JavaScript?
Jetpacks aren't widespread for important safety and technical reasons. The existence of search engines demonstrates that non-browser agents are technically possible.
Zeppelins are also technical possible. They're just not economically feasible.
People are often perfectly happy to present content as content. But when their economic interests lead them to another approach, aesthetic outrage from a tiny minority won't change that.
That latter thing isn't really a benefit. Or if it is, it's satisfying your personal aesthetic sense. I too happen to think that past version of the future was awesome. But I also liked the future where we all used jetpacks to fly up to our long-haul zeppelins. That's no reason to ban airplanes.