>>12533079That argument never hold up scrutiny.
You tell yourself "orbit is closer to asteroid = closer for our needs" but the math is more complex than that.
Mars is only at one place over its orbit and even if you launch a ship for intercept and it come back as shortly as possible the math don't match.
A launch window from Earth to a specific asteroids like Ceres will come up every year. From Mars it will be ~ every 2 years.
The deltaV you saved, you'll lose it in time if you can't afford minimal cost transfer (ex: crewed flight).
Then you consider who need the space resources the most. Most of your infrastructure will still be around Earth even if Mars could stripmine Phobos and more to make a space elevator.
If you need the resources for Earth orbital/lunar infrastructure, it make no sense to waste time making a stop by Mars as it will eat your dV budget assuming Mars is at the right place.
Lastly, be careful when comparing this to the era of sails ship. Unlike the wooden ship, spaceship can't be repaired easily, need a big infrastructure and will not carry extra fuel. It will take a century before Mars is capable of offering more than just propellant, by then it would be more interesting to set up a Jovian colony as it have many more moons and resources.