> A plain HTML site is accessible, and will be accessible in a 1000 years. A site depending on (external) JavaScript sources will force John Titor to travel back in time to find version 1.x of jQuery.
Not to sound completely apathetic, but so what? Most of us aren't building sites that we expect to be around in 10 years, much less 1000 years. The ephemeral nature of what we're building isn't lost on us - we're trading that guaranteed longevity for an improved development process (though some obviously disagree).
Frequently, writing a traditional website with any sort of meaningful UI interactions was/is kind of a mess. Most of us don't write these applications (and you're right, they are applications) because we have any particular affinity for JavaScript, but because it makes the whole process much nicer. It still sucks, it's just nicer.
Sure, progressive enhancement is a thing. And it's a great idea. In practice, top-down directives will probably be something akin to "Sure, do that, but do it on your own time and not at the expense of anything else." The realized benefits are very low (the % of users with JavaScript disabled is incredibly small), and saying something like "our site won't be accessible in 1000 years otherwise" is likely to get you mostly blank stares. It's a pretty big investment with very little benefit to most companies.
Sure, 50 years down the road if these sites still exist they'll probably be nigh-unusable without some sort of "ES6 emulator mode", but so what? I don't think we'll go wanting for any historical artifacts from this time period. If we do, it'll be because future generations have no interest in our generation - not because we didn't produce enough relics.
The arguable reason the web exploded in the first place were the architectural principles behind it were intentionally constrained to enable 50+ year sustainability and recombination for apps built within its architecture.
This isn't so much about plain-jane HTML pages (useful as they are, since they have a simple interaction model than many understand and enjoy). It's more about using and exposing data in a visible manner (known formats and semantics) and hyperlinks rather than a single page app with opaque data. This gives you network effects.
Think about the minor uproar over hash-bang URLs around 5 years ago, Twitter being the primary offender. That was single page application oriented rather than hyperlink orientation. There is a reason they've moved away from that.
In the 90s, Google or Yahoo was just something students did with the links that were out there - that eventually generated hundreds of billions in value because of network effects and visbility of the information in HTML (Ie. They could apply algorithms to it like PageRank).
The point of the web architecture is that it enables serendipity. Most anyone who has had massive success in business will explain the role of luck, serendipity, and network effects in their rise.
Designing a web app for today's paycheck by closing it off behind a WebSocket+ JavaScript mess eliminates a proven avenue for network effects. Sometimes that might be OK, but it's unnecessarily limiting for many kinds of ventures.
Not to sound completely apathetic, but so what? Most of us aren't building sites that we expect to be around in 10 years, much less 1000 years. The ephemeral nature of what we're building isn't lost on us - we're trading that guaranteed longevity for an improved development process (though some obviously disagree).
Frequently, writing a traditional website with any sort of meaningful UI interactions was/is kind of a mess. Most of us don't write these applications (and you're right, they are applications) because we have any particular affinity for JavaScript, but because it makes the whole process much nicer. It still sucks, it's just nicer.
Sure, progressive enhancement is a thing. And it's a great idea. In practice, top-down directives will probably be something akin to "Sure, do that, but do it on your own time and not at the expense of anything else." The realized benefits are very low (the % of users with JavaScript disabled is incredibly small), and saying something like "our site won't be accessible in 1000 years otherwise" is likely to get you mostly blank stares. It's a pretty big investment with very little benefit to most companies.
Sure, 50 years down the road if these sites still exist they'll probably be nigh-unusable without some sort of "ES6 emulator mode", but so what? I don't think we'll go wanting for any historical artifacts from this time period. If we do, it'll be because future generations have no interest in our generation - not because we didn't produce enough relics.