Right. I think iron is the second most abundant element on earth.
I used to work for a crack metallurgist. He said except for a few metals, there was an abundence in the earth's crust, but in lower grade ores that would be less economical and take more processing, but as we need them we'll do it.
Taconite is a good example. Here in the Iron Country of Northern Minnesota they used to mine very high grade hematite. When it began to peter out, they developed ways to process the low grade ore taconite. In developing taconite they developed pelletization, which is boon to industry. Pellets can be shipped in cold weather, stockpiled, and have limestone and other minerals added in during pelletization so that it doesn't have to be done at furnace.
There is still lots of native copper (elemental copper, not oxide or other ore) in Michigan, in very deep mines. But processing is so cheap these days that much lower grade ore in shallower mines dominates copper supply, and Michigan's deep mines are dormant.