I don't know, it may be more complicated than that.
I use google.com a zillion times a day, and it may throw all sorts of js errors under edbrowse, but I don't care because I run with

nojs google.com

In other words, I can perform the public search without js.
facebook.com is probably a nightmare, but I can use mobile.facebook.com just fine, even without js.
The question might be, which sites are high runner, and important to function properly, and also require js.
These are usually more than just browse.
Some like amazon that you order products, or paypal.com for financial, or any of the banking sites.
These are the steepest in terms of js complexity, and they may even have those nasty js tests to see if your browser is proper,
but they are among the most important in terms of accessibility.
My entire line-oriented approach / philosophy doesn't really work if I can't do my banking online.
I'd like to never ever ever have to run a screen program, that would be my dream come true.

Here's another approach: any website that puts up a message
"Your browser doesn't support javascript", and I've seen a lot of these,
we should track through and find out why it is saying that.
It's like an acid test but real world.
And it won't be easy because a lot of those tests are in try catch and don't cause any errors that we can see.
Can we somehow see errors that are hidden inside try catch?
Maybe, see duktape.errCreate and Duktape.errThrow in the programmers guide.
And there are the acid tests themselves, which we should go back to some day.
Just a lot to do, and I need about 8 fulltime engineers to help me, but I haven't won the lotto yet.

Karl Dahlke