I don't think its unreasonable for private companies not to bother to offer their services to these people. Why should they have to? Many services require nearby physical infrastructure. Electing to live in the woods is not really a disability. Plus you can just get internet out there if you want and thereby receive SMS.
You're right, it's not a disability. However, it's also not always elective. Sure, a private business has no requirement to serve people outside of the market they want to serve, but what if that business is providing a service that is de-facto required in order to access government services?
But further up this thread you're responding to it says:
> the school says "use an app or you won't get your kids" and then also say they will "call CPS and have your kids seized if you don't get them in time"
Is it reasonable for a school to "call CPS and have your kids seized" because the school couldn't "bother to offer their services to these people"?