The main issue I see is that most devs simply do not care, and/or dev management not prioritizing it unless required by regulations.
The biggest problem I see is that isn't likely ever going to change.
In the olden days, people referred to the "curb cut" — the smooth cutout at the edge of a curb that allows a wheelchair user to traverse from street level onto the curb. This turns out to be useful for UPS drivers with dollies, parents with strollers, and many other users as well.
In the digital world there are other examples, including better SEO ratings for websites that have proper accessibility and can be more accurately parsed by web crawlers.
I've found that if you present both the accessibility benefits and the business benefits, you can make a lot more progress than if you just rely on one or the other.