If you break you neck in LEO you could be in a real hospital in a few hours. From the moon it's a couple days, comparable to like an arctic base dueing a storm.

From Mars your family will only get ashes because your body will have been deconposing for months.

There is steel, aluminium and oxygen on the moon,'it can host heavy indstry and peoduce ships, space stations, equipment. It can host a space elevator today,'made of normal kevlar. You could build an aircraft carrier and lift it into orbit.