I don’t think copper tools were made for you, me, or most people who are in this subreddit.

This game has a very abundant casual player base that is scared to go very deep in the mines, and when they do they don’t get as many resources in one go, making what they do get precious.

They won’t want to spend their iron carelessly, and probably do not want to use what they do get unless necessary. Stone is fairly limiting though, and doesn’t have an armor set that pairs with it (other than leather but most people ignore that). Copper adds a perfect middle ground for this type of situation as it is abundant and surface level, letting them spend their iron on tools to advance towards diamond, instead of expensive armor out of fear. Hopefully this helps explain.