In one hand, the moon is smarter because you can have Interaction and any change takes only a week or two. While we can’t harvest local resources, the cost to location is relatively low. You could even completely run out of food and still have everyone survive

We can’t afford to screw up anything to mars when there is no Interaction and it takes 18 months or more to make a change. Imagine if there’s a medical Emergency or the garden dies: 18 months is a really long time. Everything you send there is correspondingly more expensive and everything needs to much more stock in case anything goes wrong. There are many more possible issues to plan and prepare for. This will be especially expensive until we develop in-situ resource usage

And we don’t even know if people could survive that long

• mars has no magnetic field so both moon and mars are fully exposed to radiation, but an astronaut needs to survive like 3 years of it to goto mars
• we know that microgravity causes long term health issues limiting long term presence in orbit. But we don’t know how much gravity is enough to prevent those issues. Going to the moon is short enough to not worry and gives us a second data point. Going to mars is long enough to be a serious problem if it’s gravity is not enough