I'm pretty sure there's good reasons google and facebook are experimenting with drones and balloons to extend their networks instead of satellites. A cube sat network is not something a small crypto company can do yet.

Power is probably the main issue. Broadcasting a useful signal requires a lot of power. This means big solar panels and a big antenna. So right away the design just turns into a regular satellite which costs millions of dollars to design and launch.

Reliability is the other issue. Signal interference from weather, other signals or even jamming is always an issue over a wireless network. Wired systems are much more reliable.

I like the grandiose thinking though. Sometimes it pays to aim high.