Mars: six months away at the fastest transfer. Requires multiple launches just to get the vehicle ready for the trip. If something goes wrong, everyone very likely to just fucking die.
Moon: 3 days away pretty much always. Entirely possible to send scouting parties in lightweight vehicles that can be ready in one launch. Can come home in abort shuttle if something goes wrong. Really close so good practice at making people not die from radiation and potential issues with low gravity.
Don’t get the hype with mars. It’s nearly identical to the moon in terms of being able to support human life, meaning neither can without massive work. But mars is so much further away that it’s not even funny.
PS, his first starship exploded halfway to space because he didn’t have a flame diverter like every other huge rocket has had for the passed 50 years. Forgetting basic shit like that does not breed confidence that all of the equipment you need is even going to be there.