There was a long and controversial thread on that subject some months ago.
Gist of it is, the idea that the conquest of Iwo Jima meant the difference between every one member of those bomber crews living or dying is patently ridiculous.
In any rational analysis more Americans died taking the island than aircrew saved by having the island.
You miss the point. Without Iwo, regardless of the casuelties, we had no base to launch 1000 bombers effectively.
Maybe.....If you look at it from that single dimension.
The location and the fact that there were two Japanese airfields on the island also meant that it was a base for Japanese fighters that could intercept U.S. bombers on their way to Japan.
Its capture also meant that U.S. fighters could be stationed there as escorts for bombers over Japan.
The dangers of leaving a major Japanese air base directly in your rear during the planned invasion of Japan would also have to be factored into any decision to bypass it.