The moon has a mass of 7×10^22 kg. How will wildlife on earth be affected if we mine a billionth of a billionth of a percent of its mass from the side that is never visible?
The idea is to develop a a self-sufficient industry on the moon so that you can do in-situ production of the manufacturing capacity and have it highly automated or teleoperated from Earth to minimize the number of people travelling to and from.
If it's done right you can produce pretty much everything except for semiconductors directly on the moon.
Earth ~6x10^24kg, annual human resource extraction is ~10^14kg.
(Could my figures be wrong? Its bizarre!)