That's a very bad take. Rocket costs are not driven by physics, they're driven by more mundane issues, like single-use hardware. The cost floor dictated by cost of propellant is remarkably low.
Yeah, the moment propellant drives your launch costs, you have effectively won the chemical rocket launch game.
And can then transition to more advanced stuff, like space resource extraction (so you can only launch important bits), launch loops/skyhooks/tether shenanigans in general, etc.
People think rockets use tremendous amounts of fuel, but a Falcon 9's fuel is only slightly more than half the weight of the fuel in a fully fueled 747. There's also a lot of oxidizer (about 2.5x as much as the fuel) but LOX is very cheap, the second cheapest industrial liquid after water.
