I suspect that if SpaceX plans have changed from building a colony on Mars, to building a city on the Moon first. Then there's potential to develop ISRU and related capabilities there to then build a proper intra-planetary transport which is paired with two or more 12 meter Starships that act as shuttles and cargo transport from orbit to the ground. A fully fueled Starship and Cargoship from something like this, from Martian orbit, down to Martian surface would have enough deltaV to descend and do a retropropulsive landing. Ascend again, and do it several more times before the tank is empty; arguably allowing up to 3-500 tons of cargo to be moved up and down per trip.
With just 2 ships, they can ferry up to 1kT between Moon and Mars per flight. Once complete, the ships stay on Mars where ISRU begins and the colonial transport fires its chemical engines to break orbit, then ion to generate long-duration thrust back to the moon; flip, and burn chemical again to reduce overall velocity down to manageable levels, then have ions burn again until they bring the ICT to near a Lunar lagrange point where a space tug goes and escorts the vessel back to a high lunar orbit dry dock. There its refueled by ISRU from the Moon, via an orbital depot, takes on new crew and cargo, and the process repeats.
This strategy, arguably, is more valuable in putting 1M people on Mars in 25-50 years, than launching over 100,000 Starships and 500,000 Cargoships to Mars. It also, in turn, would establish a sufficiently large presence of up to 1M or more citizens on the moon, with Terra-Luna transports ferrying goods and services to Earth orbit and potentially back down to the planet + crew and civilians. Finally having a sufficiently large population off world, at a level such, that failure to guarantee ITS survival, would be political suicide, in turn would secure colonization of Mars as well.
