Once something "free" is offered, it often pushes out paid or costly options. And it's not uncommon that this leads to a severe decline in quality. We've seen it in print media, social networks, streaming services, and many other industries. For example, we no longer have popular high-quality almanacs, and high-quality magazines at a premium price are nearly extinct. We now have a lot of "free" garbage online instead. Similarly, social networks, which are free to use, have upset the social fabric and displaced genuine deep relationships which cost money and effort to maintain. And what percentage of movies these days release on high-bitrate media? Most of us don't have access to film without blocky compression.
It's pretty clear Elon didn't think this through. There are very large risks (on the scale of his AI fears). If this service becomes widespread, regional and national governments may no longer mandate that certain areas are provided cell services for by telecoms. Or if there are faults in that system, they may delay repairs. This is all well and good while SpaceX continues to operate, but what if it goes bankrupt and the world has moved on? How many will die?
Or what if Elon has another tech bro moment and decides some region doesn't deserve this service? We know he has sometimes acted very unjustly to others, including making a decision in the Ukrainian conflict to not provide service[0]. He may be right or wrong on that decision, I won't judge. But it is clear he is inserting himself into situations he has no expertise in, and is known for casting harsh rushed judgements[1].
I think he should do it — it's quite heroic what he wants to do, but he needs to think about the consequences. Maybe the calls should always be available, but there should be a fee associated with them later, so that a cheaper local option remains relevant? I don't have the answers but I think 15 minutes of thinking surfaces so many concerns that it really does demand an impact study rather than one man making a tweet/xit.
And we haven't even spoken about potential misuse.
[0] https://www.snopes.com/news/2023/09/14/musk-internet-access-...
[1] https://www.theguardian.com/technology/2018/jul/15/elon-musk...