IMO, the unfortunate reality is cost vs benefit. If the cost of developing and maintaining accessibility/AY features is far greater than the benefit, then companies are less likely to do it. To make a stronger case for AY we would need to show the benefits. Some ways of showing the benefits of AY could be by showing significant number of disabled users, talking about temporary disability and helping veterans with disabilities.
Understandably, veterans have a special place in many of our hearts. If we can show genuine cases where AY helped a significant number of veterans, then it might make a stronger case for AY. There are no guarantees, but it might make people more interested and aware about AY, if not anything else. IMO, awareness is a critical 1st step. If your leadership is not really aware of it, then you first have to make them aware and then make your case for why your company needs AY. They might avoid it due to higher priority items, which are always present.
Temporary disability (broken arm, eye surgery etc.) - I think this is one way to remind able bodied people that they could need AY too. So, they should educated themselves about AY & try to add at least some AY features. I had seen one link with excellent examples of how able bodied people might end up needing AY features, but I can’t find it. But here is something which talks about temporary and situational disabilities - https://download.microsoft.com/download/b/0/d/b0d4bf87-09ce-4417-8f28-d60703d672ed/inclusive_toolkit_manual_final.pdf
Another thing we could try is to see how able bodied users could benefit from AY tools. This might not be possible in in all cases, but I can think of one case. I’d like to have news articles read to me instead of reading them myself, so that I can do other stuff in parallel. Maybe I could benefit a little bit from some AY tools too? I think Wall street journal has a read button for their news articles. That is not an AY tool, but it could surely help blind people read the news if its combined with AY features for blind people.
As an aside, perhaps we could have an open source repository of AY design, code, testing, tools etc. Maybe this repo could be made by big, wealthy companies who have budgets for AY. Smaller companies with low budgets could use the repo instead of getting intimidated by costs & giving up without trying. But, I am not sure if big companies would want to give away their investment for free or even make it open source.
Doing AY is a noble goal indeed. But, I sometimes wonder if the people who advocate very passionately for AY have an idea of the costs involved and the challenges which a business faces.