I think it would be a good idea to define a subset of the current web technologies and make all important sites like banks, tax office etc. to adhere to this standard basic functionality. It also needs a logo which can be used on these sites.
We used to have such a thing: it was called HTML. Sites were supposed to have their content in the HTML, and if JS wasn't enabled, you'd still get the semantic hypertext. A vast majority of web pages are text and images, and don't actually require fancy CSS/JS. But the ship of progressive enhancement has long sailed,[0] and tons of static sites have JS, and all the hundreds of APIs that entails, baked into their functionality. Hell, there are many sites nowadays that will use JS to stream the HTML to your device for some reason.
[0]: JQuery/AJAX were probably the beginning of the end. But even without those, you had developers doing things like putting main images in CSS using the background property, overloading text with icon fonts, loading videos using "blob:" crap, or other abuse of semantics. Once it became possible to push more state to the browser instead of the server, the floodgates opened. I remember in the dial-up days, you could take a browser offline, and webpages would function perfectly, yet now, even hitting the back button can be a gamble. Now, hitting File > Save fails 95% of the time for me.
