> its not clear what other markets SpaceX can grow into. The rocket market is small

Ten years ago, smart people said the launch market couldn't possibly grow beyond $3 to 5bn.

There is a tonnne of induced demand when it comes to launch. In LEO alone we have telecommunications, sensing and defence applications, most of which don't do well when put on the same bird. Add to that potential power-transmission uses and a global race to the Moon and Mars and it seems even if Starship can be mass manufactured, production will be the limiter, not demand.

> combined with Starship launch will be so cheap that it can compete against some broadand on the ground. But that seems speculative

Doubtful for broadband. Probable for rural and maybe even suburban cellular.