Typically, It’s Not That Simple.
Let’s ignore the cost of a satellite capable phone, which would maybe double the cost of a smartphone.
You’ve got two options here, geostationary satellites or low Earth orbit satellites.
Satellites comms requires line-of-sight to the satellite. With geostationary satellites you’re going to get shedloads of blind spots all over the place (and they’re also tremendously expensive). LEO satellites largely negate blindspots by nature of being on the move, so long as you only want to make ten-minute phone calls whlist the sat passes overhead.
You’ve also got latency issues; you’ll have, what, half a second to a second of delay maybe, on your conversation. Fine for consumers perhaps, unacceptable for corporates.
Finally, data. weeeell, good luck with that.