The landing doesn't have to be successful. If a Starship hits Mars at high velocity, that counts. It does have to hit the ground. Just aerobraking isn't enough.
/Mqrius/will-a-starship-land-on-mars-before
@JonathanRay You can still do that with Starship, you just use a second one or a depot. That's one of the ways in which you can do a Mars landing quite soon without needing any in-situ propellant generation. If they finish the tech to land on the moon, they pretty much have the tech ready to land on Mars too, assuming they have boiloff mitigation done as well.
Yes, it'll require more launches, but that's not a technical problem, just a financial one. With Starship being designed for cheap mass production and cheap launches, the financial problem is not as problematic as it seems either.