Because it's not on the browser to fix it, unless it provides screen reading capabilities of its own, which e.g. Google Chrome doesn't. Instead, Google Chrome s

Because it's not on the browser to fix it, unless it provides screen reading capabilities of its own, which e.g. Google Chrome doesn't. Instead, Google Chrome specifically will make a so-called accessibility tree available through whatever APIs for external code to parse and evaluate. The relevant parties involved are the websites hosting the content, the people producing the content, and the developers developing the screen readers (and potentially the admins who control the screen reader application that is deployed). None of these are the browser.