There is no way that we would have defeated the Japanese by 1945 if we did not Island hop. Hell it took Mac Aurthur till late 44 to take the Philippines back.
We needed a base close enough to bomb Japan from and that was Tinian next to Saipan.
We did not have the modern equipment, doctrine or technology to go straight to Tinian and Saipan.
Further the naval Battles those island campaign caused gutted the Japanese Naval, Naval Air and Airforce. Another needed ingredient.
Some of you need to actually read the history of the Pacific War. Every Island we took was needed as a chain to allow us to take Tinian and Saipan. After that they were needed to protect the Bombers or in the case of Okinawa, give us a base close enough to invade Japan.
Even after 2 Atomic Bombs, the gutting of their industry, the inability to feed their people, the inability to provide fuel for winter fires, the Japanese Army REFUSED to surrender.
The ONLY reason Japan surrendered is that after the second Atomic Bomb the Emperor demanded a surrender. Even at that, the order from what they considered a "living God" the Army attempted a Coup to prevent the Emperor from surrendering.
And do not even start on the bullshit claim that the bombs were not needed. I have SOURCE documents to back up what I just said.
As for the Army in the Pacific, they were timid and half hearted up until Okinawa. Hell Mac Aurthur used the Australians for the tough jobs in his drive..
One Army General was relieved of Command at Makin ( Tarawa) for refusing to advance on an island abandoned by the Japanese. His timid and ineffective use of his troops tied up the back up forces for Tarawa.
MacArthur believed the Australians were not good troops and used them as little as possible, in fact, after Australian New Guinea was taken they were no longer used in the drive to Japan. The army and Marine Corps fought differently, as hated as MacArthur was his casualty rates were low and he did, perhaps because he had the room, avoid taking islands like Iwo and Tarawa. I think even Howlin Mad suggested Tarawa was an error. And the Palaus a total waste.
The intent of the central Pacific campaign was inadvertently revealed by Sec. of the Navy James Forrestal in 1945: "The raising of that flag on Suribachi means a MARINE CORPS for the next 500 years."