Unapologetic,
I asked that same question when when Edward Snowden was in the news and, much to my surprise, the overwhelming bulk of data was still sent by cable and still is to this day, though this is changing.
The Battle for Bandwidth: Submarine Cable and Broadband Satellite Data
The Battle for Bandwidth: Submarine Cable and Broadband Satellite Data
My thought was that perhaps Musk and others as wealthy as him could change this by making satellites more ubiquitous, durable, and powerful, and networks more resilient. If Musk and others could succeed at this, Internet commerce and culture could reach even more people on Earth and this could mean more innovation and prosperity on Earth that could be invested towards exploration and settlement in space later.