It's my firm belief that mobile devices ARE assistive technology in and of themselves in certain respects.
iPhone products with Voice Over, android devices have accessibility features, and most phones of course allow voice input for search -- a HUGE time saver for those who have difficulty typing....
1. They enable those with disabilities to communicate from wherever they are, rather than having to come to a particular work center to access assistive technology.
2. Cheaper to attain, cheaper to maintain than full desktops
3. See this quote from the WebAim 2016 screen reader survey "Those with beginner screen reader proficiency were much more likely to be using a mobile device than those with advanced proficiency."
What this means: the technology itself will be more inclusive.
What this ALSO means: more people will be able to help those with disabilities, since phones are a common piece of technology that most people use. You don't have to be an expert on EVERYTHING about the phone to help someone with disabilities.