Apple has already invested heavily in accessibility across all of their platforms. The market for hearing aids is far larger than some of the tools that they currently deliver.

https://www.apple.com/accessibility/

While Apple is arguably ahead in the quality and features of their accessibility technology, the potential convergence of hearing aids and voice based tools means that Google, Amazon and Microsoft are certainly looking into this.

Accessibility doesn’t require FDA approval.

we're living longer, going deaf earlier, and believe that our phones can do nearly anything. The market keeps getting bigger and bigger.

Does there really need to be a hardware difference between AirPods and hearing aids down the line?