A11y overlays
JavaScript-based "overlays" promise accessibility as a convenient add-on, but very much fail to deliver.
So-called "accessibility overlays" represent technological solutionism in its purest form ("don't worry about inclusive design, you can fix it with a few lines of code later") and opinions are manifold why using them is a bad idea. Their claim of compliance with legal requirements is at least disputed, and from a user's point of view they -- unsurprisingly -- don't seem to deliver on their promise.
Maybe the most comprehensive resource collecting opinions and evidence:
Honor the ADA: Avoid Web Accessibility Quick-Fix Overlays
Some other good readings:
Background: Should I use an accessibility overlay?
#accessiBe Will Get You Sue
Karl Groves has authored a fact sheet, collecting arguments, evidence and signatures:
