It will solve problem of cross site tracking. However lot of sites will break because of their over dependence on javascript.
Have you ever tried browsing by turning javascript off. A lot of garbage just does not get loaded.
It does seem like WebAssembly is the answer here, but would be cooler (I think) if that sort of thing was built from scratch.
Chrome: Turn off Javascript support - chrome://settings/content/javascript
Firefox: Install NoScript and disable Javascript support.
Both have the advantage that you can whitelist sites that you trust.