Mining asteroids wouldn’t be for Earth - it would be for satellites or LEO or possibly even Mars, which is a lot closer to the Asteroids than Earth and may need some extra raw materials we don’t want to spend the horrendous cost of lifting out of Earth’s gravity.

The Moon has nothing to offer Mars explorers as everything will be different and solutions for the unique lunar conditions (two weeks of darkness, temperature extremes, moon dust, vacuum) do not apply to Mars at all. It’like saying living under the ocean is good practice for living in the Artic, but we should start under the ocean because it’s closer.