Could someone use AI to make the GPUI kit become accessible? You (or someone else) mentioned that it doesn't even have the primitives so is it a non starter?

No, I mentioned that most rust UI toolkits lack even the primitives. The primitives for even basic accessibility, without accessibility frameworks, would be things like focus events, carrot navigation, navigation in containers such as list/combo boxes, line/paragraph handling in multi-line edit boxes and the like. Adding native accessibility forces you to do a lot of this but just in a different way than routing text directly to a screen reader.

As for me doing it? According to prior comments in this thread it's already done, although I haven't tested it so I don't know how complete it is. Adding UIA support to a framework is different from making that support good (screen readers can be very picky). As an example, say you have a label of an edit box. If you position the label just right within it's parent container a screen reader will pick it up automatically and just announce it as you focus the edit box. But if you don't, all you'll hear is "edit <contents|blank>". There are ways around this (e.g., you can override label detection) but the "ideal" state is that the screen reader picks up that stuff automatically and you just give it the bounds of the various controls and UI elements.