We have working systems like the Tongue Drive System (TDS) [0]. Tech companies seem out there [1] or [2] that offer solutions, but the a11y market is largely dysfunctional across the globe.

It is so difficult to get everyone the tech that works best for them. I was part of large EU funded project that wanted to fix this with an open source ecosystem [2]. However, I had to learn that although there are many innovative and engaged people it is really hard to fix seemingly simple problems.

[0] https://www.science.org/doi/10.1126/scitranslmed.3006296

[1] https://glosdex.com/

[2] https://tongo.tech/

[3] https://ds.gpii.net