Let’s give a concrete and catastrophic example of something I’ve seen in the wild in a professional product. A developer there had obviously seen the application role[1] in the ARIA specs, thought “I’m building a web app”, and added it to their html element.

What role="application" means to assistive tech is: “I’m building a really complex application, so I’m going to handle absolutely everything for you, I don’t want you to have any default behaviour.” This meant that the web app in question was 100% unusable for any people using assistive technology, as that was broadly as far as they’d got with accessibility support.

[1] https://developer.mozilla.org/en-US/docs/Web/Accessibility/A...

That does seem catastrophically misguided. I’m more curious about the more common case where tags are used as documented (and I really wish the documentation was better), but perhaps not completely. For instance we have a Finder like UI in our web app that conceptually is a treegrid, but we don’t support all of the keyboard interactions advised at the above website.

Should we remove the role attributes?

Stories like this make me wonder if we could build a Chrome extension with a collection of crowd-sourced site-specific accessibility tweaks. Things like removing that bad ARIA tag or bodging in proper labels or tabindexes. It wouldn't be perfect, but neither is AdBlock and it offers a lot of benefit.