I'll believe that once I see you file an issue which mentions accessibility against any of the projects I linked to ;-)
https://github.com/facebook/react/issues?q=is%3Aissue+author...
https://github.com/vuejs/core/issues?q=is%3Aissue+author%3As...
https://github.com/sveltejs/svelte/issues?q=is%3Aissue+autho...
Simon don’t waste your time with this guy. I thought he was affiliated with htmx but he’s just some dude trying to prove he’s “right”.
Now if you say that component frameworks like shadcn/ui or whatnot should implement accessible behaviours and patterns, I am 100% with you on that. But React/Vue/htmx are at a lower level, they can't decide those things for you.
EDIT: sure enough, someone filed an issue with shadcn/ui that it does not announce something properly in screenreaders: https://github.com/shadcn-ui/ui/issues/4209
EDIT: here's the one mention of `aria-live` in the React.js codebase defining it as a valid ARIA attribute for ReactDOM: https://github.com/search?q=repo%3Afacebook%2Freact%20%22ari...
The one mention in Vuejs core to define its accepted values: https://github.com/search?q=repo%3Avuejs%2Fcore%20%22aria-li...
The one mention in the Svelte runtime defining its accepted values: https://github.com/search?q=repo%3Asveltejs%2Fsvelte%20%22ar...
Do people go after these frameworks saying they need to handle breaking screenreaders by dynamically updating content? Of course not. Setting live regions is the responsibility of the web page creator, not the framework.