Have you ever checked out uMatrix? It's a chrome plugin that lets you control which javascript can run on a page (and allow some by default across the web based on where it's loaded from).
That's a nice idea, but it's not a solution. The real solution is to make content accessible, rather than depending on JavaScript. Apple has terrible form in this regard.
Pragmatically, I think that ship sailed a decade+ ago.
You're not wrong though...
developement of uMatrix is no more.
There is a fork 'nuTensor' with stated intention of continuing development/maintenance (with a Firefox focus):