ramps (by parents with babies in their strollers), subtitles (by people learning languages or in loud environments), audio description (by truck drivers who want to watch Netflix but can't look at the screen), audiobooks (initially designed for the blind, later picked up by the mainstream market), OCR (same story), text-to-speech, speech-to-text and voice assistants (same story again), talking elevators (because it turns out they're actually convenient), accessibility labels on buttons (in end-to-end testing, because they change far less often than CSS classes), I could go on for hours.
For user interfaces specifically, programmatic access is also used by automation tools like Auto ID or Autohotkey, testing frameworks (there's no way to do end-to-end testing without this), and sometimes even scrapers and ad blockers.
Getting ratioed because people think “my app must follow accessibility for… oh.. uh… because big company does so we must do same ooga booga smoothbrain incapable of critical thinking”
Waste of time unless you are aiming your application AT people who use screen readers e.g. medical or public sector. EVEN THEN has anyone actually tried? Even accessible websites are garbage.
