It probably isn't. Most mission critical problems and bottlenecks are resource depletion problems, and those can be easily solved by just sending a shitload of resources to Mars before sending people.
Need to scrub CO2 from the air? Nope, I'll just send over 10 extra cargo starships filled with Oxygen. Food for 100? Coming right up!
The whole plan hinges on making enough money with starship that sending up 100 rockets with triple-redundant resources becomes economically viable. At that point, you can slowly start building a somewhat self-sustaining infrastructure. But until you get there, the plan will just look foolish.
Need to scrub CO2 from the air? Nope, I'll just send over 10 extra cargo starships filled with Oxygen. Food for 100? Coming right up!
The whole plan hinges on making enough money with starship that sending up 100 rockets with triple-redundant resources becomes economically viable. At that point, you can slowly start building a somewhat self-sustaining infrastructure. But until you get there, the plan will just look foolish.