It's an erosion (however minor, by itself) of the idea of an open standard.
https://github.com/apple/password-manager-resources
Many of these sites are quite obscure.
For being "quite obscure", I've at least heard of most of these sites before. Banks with "maxlength: 8", you love to see it.
In this case, getting those companies to fix their broken code is unrealistic. Less realistic than just providing a whitelist anyway.
Well that is a good way of ensuring that the same class of problems will endlessly reappear, while also providing a broken utilitarian end-justifies-the-means rationale that is certain to be abused.
> The standards are important, but they're ultimately there to provide a nice UX and that's it.
No, standards are there to make interoperability possible, which overcomes the hazards of market network effect, leveling the field for more competing solutions, thus yielding a better <insert literally anything in the whole world, including UX>.
Develop Menu > Disable Site-specific Hacks