Get rid of most of JS to prevent 'appification' and keep the focus document centered. Edit: I think this would result in protocols over walled gardens. The problem is JS makes HTTP/HTML everything to everyone.
Be careful what you wish for. JS and HTML5 is why we don't have Adobe Flash anymore. There was a whole period in the noughties when web interactivity sucked and so external plugins like Flash, Silverlight and Java applets took up the slack. The alternative to JS is not "no scripting", it's websites that only function with proprietary plugins installed.
Flash got axed because the way it was implemented into clients was wasteful, insecure and a bad user experience in general. Same with Java; you can't make the same tools that Java applets once provided through the browser because of the browser's security model, so I'd say the two never competed.
Making a quick interactive animation that works across all kinds of resolutions and sizes was trivial in Flash, but in HTML5 this is a challenge. HTML5 and friends fixed the problems that made web developers grasp at Flash for, like file uploads, animations and predictable interaction with the mouse and keyboard. These features were often already possible in browsers, but Flash was the only tool that made them appear the same in every browser available. They didn't replace the flash scene for games, interactive simulations and other online experiences. The Flash game scene pretty much died when Flash started getting blocked by Chrome, with only a small subset of the community fragmenting and finding their way to frameworks like Unity Web and its then plentiful competitors with high learning curves because they were designed for the "real deal" game developers rather than self-taught animators that turned game dev.
I think JS is a necessity for the web to exist today, but we need an alternative for what once was Flash, Java, Shockwave and more. Too many features have been shoved into HTML and Javascript that have no business there, left to be abused by trackers and hackers alike.