Are you working on a WEBSITE? Then YES, you should have written the FULLY WORKING PAGE WITHOUT JavaScript FIRST!!! Now, if you're building a full stack web crapplet like with nw.js, electron, metro, etc, then you can go hog wild, but if we're talking websites. Oh HELL NO!
Particularly if your site is for government organizations, non-profits, healthcare, banking/financial, as such sites are often LEGALLY required to meet standards such as WCAG 2.0, in which case scripting off is MANDATORY.
In fact, my specialty that keeps dragging me out of a perfectly good retirement is helping sites facing fines, civil litigation, and breach of contract fix such problems, which 99.99% of the time some scripttard pisses all over the page with their goofy halfwit incompetent garbage (see "jQuery") involves tossing the entire site and everything they've already thrown money away on into the trash.
There's an age old unwritten rule about JavaScript for websites:
If you cannot make the website fully functional without JavaScript FIRST, you likely have zero damned business adding scripting to it!
Good JavaScript should ENHANCE an already functional page, and not be the only means of providing it.
"Enhance" being the key word, as said philosophy is part of "progressive enhancement" which is the only practical way of building a site that will gracefully degrade. Graceful degradation -- Scripting off, CSS off, images blocked, etc, etc -- is an essential part of building HTML properly since your markup is for EVERYONE, not the magical mix of screen resolution and browser capabilities you happen to be fortunate enough to be privileged with!
Intentionally blocking JavaScript out of distrust, excessive CPU use wasting battery time, the increasing number of places where bandwidth caps are enforced and overage charges get involved, yadda, yadda, ditto, ditto is becoming increasingly common. Just look at the number of people installing browser extensions like NoScript, Ghostery, ScriptSafe -- basically users fed up with the "gee ain't it neat" JavaScript bull telling site makers who insist on slopping megabytes of scripttardery onto pages that probably shouldn't even NEED JavaScript to go plow themselves.
JS for nothin' and your scripts for free. That ain't workin', that's not how you do it. Lemme tell ya' these guys ARE dumb.
<broken record> It's like what I'm ALWAYS saying about jQuery in that EVERYTHING I've ever seen done with it falls into one of three categories: 1. Things that would be less code without the framework not counting the size of the framework against it. 2. Stuff that's HTML or CSS' job and can be done without JS entirely. 3. Garbage that has zero damned business on a website in the first bloody place. </broken>
Those latter two apply to well over three quarters of ALL JavaScript I see used on websites. To then have such mind-numbingly idiotic halfwit code bloat banging the brakes on accessibility AND performance? To blazes with that type of thinking.
But of course, everyone wants their "gee ain't it neat" flashy bull slopped on top to cover up for a lack of unique content of value. You'd almost think the web was being taken over by scam artists who's entire goal in site "design" is little more than dumping a can of shellac on a pile. No matter how clear a shine you buff it to, the end result is still just bug excrement on horse manure.
But let me tell you what I REALLY think...