We knew how to keep people alive on the way to the Moon, alive on the Moon, and had a reliable way back. We didn't start off the race by declaring our intention

We knew how to keep people alive on the way to the Moon, alive on the Moon, and had a reliable way back. We didn't start off the race by declaring our intention to colonize the Moon. So I look at the issues which made Mars 'hard' a while ago, and whether or not they're solved or if Musk is on the way to solving them. Micrometeorite shielding. Not solved Radiation shielding. Not solved Long term microgravity health effects. Not solved Sufficient understanding of the human microbiome to keep it thriving off-world. Not even addressed