Today's useless advice about making technical online content accessible, from my university's head bureaucrat for online content accessibility bureaucracy (but I repeat myself):
"I would recommend avoiding PDFs altogether. They are extremely difficult to make accessible. If PDF format is absolutely necessary, create a document in Microsoft Office and then save it as a PDF."
Meanwhile, TeX Live 2026 + ltx-talk has been working for me in making pdf-format slide decks that pass all Acrobat accessibility checks, and I have moved on from experiments in using it (https://11011110.github.io/blog/2026/03/01/making-accessible-latex.html) to using it in production for all my course lecture slides. There is no real alternative to some form of TeX for content involving mathematics. This works. And if you're already using LaTeX + beamer, it's not difficult.