For starters you're acting like the US played a large enough role to learn something from it, which they didn't. America didn't declare war until April 6th, 1917 and troops didn't arrive on the western front until the summer of 1918, meaning they fought in the Kaiser's Offensive, the last battle of the war. If there is one thing that stands out about this last offensive is that it was a lot more mobile than previous engagements in the West. I would argue than other than second hand accounts the American military would not have seen much of the hopeless trench warfare that other powers saw, and instead their largest contribution to the Allied war effort was capital and goods. After the war as well America returned to their foreign policy of isolation; refusing to join the League of Nations changed by Woodrow Wilson ironically enough. Why would there be any need to create a force to fight in Europe, eespecially when you had no plans to return to Europe to fight again; it simply would not make sense. You're also overvaluing the contribution of tanks to the First World War, most militaries did not really use them. The first fully mechanized force doesn't show up until 1944, by most opinions I've heard, with the invasion of Normandy. Tanks in the First World War were not seen as very useful, in one sense they were great as bullet sponges, but they were slow cumbersome beasts that were not seen as hopeful for the future. It really was not until the German invasion of Poland do we see how useful they can be, German blitz warfare is what popularized them rather than the First World War. Without being an expert on some of this though the Sherman was made in 1940, the Mustangs first flight was in 1940 and the P-36 and B-17 were in service in the 30s, the M1 Garand was in service in the mid-1930s and the US had a large carrier fleet in the Pacific before war broke out. I don't see how can you draw the conclusion that they weren't modernizing in the lead up to the war, they focused heavily on naval engagements in the Pacific maybe, but the US had a military that could, and did, go toe to toe with the best in the world and came out on top. Also, a pet peeve I have to mention WW1 did not introduce airplanes, the machine gun or modern artillery to warfare. So if anything would have impeded innovation it would have been isolationism in my opinion, but I don't think you can draw that conclusion at all.

You also are rather selective in your examples.

We have plenty of areas where the US was either first rate or way ahead of everyone else.

1. Is Radar Fire control, especially for main batterys, well before the entry into the war the USN was becoming a strong follower of the potential for radar controlled main battery fire for surface ships. The USN was also an early adopter of Radar directer fighter intercept. meaning a guy on the carrier told the defending fighters where to go to intercept contacts. the IJN meanwhile basically told its fighters to keep an eye out and look to see if the ships start shooting at stuff.

2. The pervasiveness of radios. While the Germans get credit for proving how important radios were in modern combat nobody used them more than the US. Platoon and below sized elements would most of the time have them and every aircraft large or small would have one. Very much not always the case of their foes.

3. Dual purpose artillery, along with the British the US int he early 30's committed to the idea of one secondary armament and light armament that was good for both surface and air action. In the US that took the form of the 5"/38 Caliber gun. Simplifying fire control, supply, and general operation in combat. The Kriegsmarine never got it right hence the Bismarck's having both 5.9 and 4.1 in guns aboard.