I see the misunderstanding. You're assuming that cancellations would still be handled by humans shuffling paperwork, whereas I'm optimistically assuming cancell

I see the misunderstanding. You're assuming that cancellations would still be handled by humans shuffling paperwork, whereas I'm optimistically assuming cancellation would be handled by computer software, much like it is when you cancel an exclusively online service like Netflix. Though even in your scenario, you are assuming that a company wouldn't adjust its resources as telephone usage drops and written submissions increases. And yes, the point you make in your second paragraph also applies—a written cancellation request places the time onus on the company rather than the customer. But either way, it is always a good thing if the methods used by people with disabilities are mainstreamed rather than treated as oddball special exceptions.