Several HTML elements are mapped to ARIA role generic; e.g. <b>, <i>, <samp>, <small>, <span>, <u>. However, most (all?) browsers don't expose them in the a11y tree unless they have other properties (tabindex, etc.) that force them to be exposed. Currently, all three browsers fail for all of these3 tags.

This leads me to question whether the spec is realistic here. It's reasonable to map these to generic when they are included in the a11y tree. However, browsers exclude them (if inclusion isn't forced) to keep the tree from becoming needlessly deep and to improve performance.

I don't see anything in the spec that currently makes inclusion optional. Inclusion is optional for elements which are "not mapped", but no such affordance is given for generic.