I doubt that. Monetization is a goal of most of these platforms, which makes the JS and privacy-hostile stuff absolutely intentional and implemented with malice aforethought. There's no reason to require client-side computing for the vast majority of sites, and the remainder are relatively niche webapps. Media-viewing sites aren't niche, and have good UX reasons, but I'd bet the vast majority of use is outside of the web interface anyways (ie. on mobile).