They would have the advantage of variable density based on demand, i.e. more of them over population centers and none over oceans, whereas LEO satellite constel

They would have the advantage of variable density based on demand, i.e. more of them over population centers and none over oceans, whereas LEO satellite constellations are pretty uniformly distributed because they're orbiting. It's sort of in between a stationary cell tower and LEO satellite constellation. But then you have to worry about them failing and hitting those population centers, whereas satellites deorbit slowly and usually burn up completely.