In an earlier post I presented a bookmarklet that regularizes the color scheme of a visited site. The bookmarklet below solves a different, and growing, readability problem: the habit of sites to encroach on the material you came to read — intruding from the bottom, sides, and top of the screen. And to pop up / pop over obscuring cruft that offers a subscription or a coupon or an auto-playing video that you had the temerity to scroll away from without clicking.
I use the bookmarklet below every time the visited page has a Cookie Notice at the bottom or social media widgets obscuring the text to one side or a banner covering the top that appears if you scroll back up the page.
It simply removes the cruft.
Drag the link to your bookmarks bar and when prompted, give it a name. I have named mine “-sticky.”