It's almost like they want to make sure it works for the vast majority of people before they spend time and effort making it work for a much smaller segment of their userbase.
When you have an accident waterskiing and end up on crutches, you'll be glad for the accessibilty of doors that open with a button press. When you poke your eye hiking and need to wear an eyepatch for a few weeks, a screen reader might not seem such a niche use case.
These are even kind of extreme examples: frankly, even stuff like dark mode that we take for granted at this point is an accommodation to how some people need or want to use their computers. Migraines are a good example of an (astonishingly) common condition that benefits from flexibility around having to stare at a screen.
None of us gets younger as the days go by, either, and that comes with changed needs. I'm still thirty years from retirement and I find that the 10 point font I used to prefer isn't good enough anymore. Bumping up text size is a quotidian action for me and millions of other people.
ADDITION: Ah, finally found the quote I was looking for. Maybe not directly relevant, but thought-provoking:
> SMS texting was invented [to] figure out a way for deaf people to communicate with one another without speaking. ... Now text messages are universal.
https://blog.ai-media.tv/blog/why-designing-for-accessibilit...