I haven't taken measurements, but there are many problematic sites these days. Lots of web developers fail to see the problems that javascript imposes on users, so they build web apps even when they're serving static content, where a regular web site (perhaps with javascript enhancements that aren't mandatory) would do just fine.
I selectively enable first-party scripts on a handful of sites that I regularly use and mostly trust (or at least tolerate). Many others can be read without scripts using Firefox Reader View. I generally ignore the rest, and look elsewhere for whatever information I'm after.