Yes ... if you have enough "stuff" to fill the thing. There will continue to be a market for medium and small launch vehicles. Rocket Lab, for example, is doing quite well in the small launch market.
Musk needs Starship to lift his Starlink V2 satellites. Falcon can only lift the “V2 mini” version.
Starship can also act as a space station module, and a way to recover failing large satellites.
With a low enough cost-to-orbit, we can do things like another Webb Telescope.