Offline files and paper files are not easily accessible. You have to be able to open a file to be able to use assistive technology or UDL Technology with it. Every browser, operating system, and device have a ton of UDL/assistive technology that can be used to better access files. This can be speech to text, text to speech, closed caption, and optical character recognition. The fact that files can be accessed online helps tremendously with executive function and supports students with receptive language deficits that need written direction. Sharing the documents with special education teachers and parents allows them to create structure and set goals for students. More parental and teacher involvement can help create a dialog about work and accountability. There are devices that can help make paper documents more accessible. They are expensive and not widely used.
The math about how many students need accessible files is simple. At least 20 percent of students are special needs students. The real number is actually higher, and that does not include students with other issues. Students that speak English as a second language also benefit from a number of online tools in order to fully access school material. Take the number of students in a public school district and multiply by .20. Private schools might possibly have lower numbers if they are not schools that cater to special needs students. However, students need to be able to access school work. Basic ethics dictates this. Many of the laws we have for disabilities are about access. Being able to access documents is something very important and something every student should have.