You are dismissing again the answer you are getting. Why do you think it is lacking accessibility despite using a framework claiming " GPUI Kit ships 75+ documented components and primitives, WebAssembly support, AccessKit accessibility"
It's reasonable to be concerned that Discord may not have focused on accessibility while rewriting.
It's less reasonable to be concerned that it may be impossible to write accessible apps using GPUI, as that is now possible (https://github.com/zed-industries/zed/blob/main/crates/gpui/...) although this is a fairly recent addition.
It's also less reasonable to assume that an app made with GPUI Kit will automatically be accessible. You still need to put effort into it.