I think the main idea for starship is fully reusable ( which falcon 9 isn’t) and much larger capacity (both volume and mass). Driving down the cost of getting mass to orbit.
I googled and got the following costs per kg to orbit Falcon approx $3000 / kg Starship (early) $600 / kg Starship (target) $ 100 / kg
If they can achieve the target, it’s transformative. The Chinese will follow the lead and be available for some commercial customers but the majority of the market will be SpaceX.