That page also lists examples of semantic and visual uses of bold and italics, which sound pretty reasonable to me. As for it not being critical due to inconsi

That page also lists examples of semantic and visual uses of bold and italics, which sound pretty reasonable to me. As for it not being critical due to inconsistent screen reader support--it sounds like a chicken and egg problem. If developers don't use those tags consistently, then people using screen readers have hard time with them, and so screen readers adjust. In any case, if it doesn't hurt but can potentially help, I personally prefer to use semantic tags to convey the meaning and visual styles for pure visual effects.