If you're linking to local elements via id you must ensure that they are focusable because otherwise assistive technology relying on "document.activeElement" can't follow the link target.
Topic: Accessibility – Page 2
Should browsers ask you what you wanted to tap if you hit two elements?
A quick note about Manuel Matuzović's discovery of Safari not being able to focus zero-size elements.
It's common practice to sometimes overwrite an element's visual label with
aria-labelto provide more accessible information. As it turns out, this could break speech recognition software.em and strong elements are not announced by assistive technologies such as screen readers.