This is, to be blunt, narrow-sighted; most accessibility support is rooted in best practices for
every user. Screen readers are only one use case, other things that people don't even consciously think about and take for granted when they use a webpage or app are things like zooming in, focus/reader modes, light/dark modes, performance, print views, copy/pasting content, SEO / searchability, bookmarkability (e.g. headings & anchors in webpages, also used by screen reader users to quickly navigate a page), etc.
99.99% of accessibility things are covered if you just follow normal, established software development practices. Unfortunately, a lot of software developers overcomplicate things, for example by adding modal dialogs to websites. Modals are common and established design patterns in desktop apps, but not so in web and mobile apps. Applying one environment's UX patterns to another is asking for trouble.