I think at this point most people, even in poor countries, have access to cheap mobile phones. Even cheap used ones. I think if someone does not have a cell phone it is probably by choice.
I acknowledge some people are really poor and could never afford it but they are probably living life where anything happening online is not their concern as they must have bigger issues to deal with.
If it's just to sign up to Steemit or some type of 2 point verification they could just ask a friend or neighbour, co-workers, they must know at least one kind person who can accept a text once in a while.
Just my thoughts. Nice post.
Its not the phone it's the subscription. Look people can save up for stuff but they can't always afford a regular output of money for a subscriber fee. Consider the difference between giving blood and slowly bleeding over a years time. The former your body can handle, the latter will do you serious harm if not kill you. Also a lot of people access the net using internet cafes or public access points. So your presupposition that just because you can't afford to put out $80 a month on top of an internet fee (which can run around another $80) that some how they don't have any business online is false. Assume they can't afford the initial $80 for their internet. That means they'll turn to using a public access point like say the Library. That doesn't mean they won't care about anything online. In fact many government services depend on internet (ironically enough) so if you are that poor you're likely on welfare and REQUIRE internet access just to deal with the bloody beaurocracy.
But as I said it's not the cell phone it's the service that makes the difference. Not every carrier will allow you to use a used phone (prepaid) as some require you to have a contract with them. Others incentivise you by giving better deals to subscribers so really it comes down to the difference being the subscription fee.
I still don't think users should be cut out of the system for lack of a cell but borrowing a phone might be a temporary work around.