1) Why do you think people in subsaharan Africa, for example, won't be able to use it?

2) The only limitation on bandwidth (and thus users) is the number of satellites in orbit. If the constellation bandwidth is saturated, launch more satellites and you get more bandwidth.

3) I guess you'll just ignore the use cases for the tens of millions of non-rich people who literally can't get decent internet because it doesn't exist where they live?