https://en.wikipedia.org/wiki/Operation_Downfall#Considerations

Could the allies have just avoided or starved Iwo Jima and Okinawa and main home islands instead of land invasions?

The United States Navy urged the use of a blockade and
airpower to bring about Japan's capitulation. They proposed
operations to capture airbases in nearby Shanghai, China, and
Korea, which would give the United States Army Air Forces a
series of forward airbases from which to bombard Japan into
submission.[26] The Army, on the other hand, argued that such
a strategy could "prolong the war indefinitely" and expend lives
needlessly, and therefore that an invasion was necessary. They
supported mounting a large-scale thrust directly against the
Japanese homeland, with none of the side operations that the
Navy had suggested. Ultimately, the Army's viewpoint
prevailed.[27]

Why did the Army's viewpoint prevail?