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Well, the Hurtgen Forest was more deadly from German blasts overhead into our troops into the top of foxholes and trenches - perhaps that is the effect that you're thinking of. But the German's had no proximity fuses. (They did have a few working models of remote-controlled aerial glide weapons and heavy glide bombs used against ships. But those were handicapped by being developed very late in the war, when little avgas and trained pilots were available.)

The USN anti-air proximity fuses were tripped by a small radar set in the fuse. The German overhead blasts in the H. Forest were triggered by conventional impact fuses (super-fast fuses) triggered by the fuses hitting the tree limbs and upper branches.

Equally important, the Germans were finally fighting on their own soil, and the US troops were no longer able to get intel from the local civilians. Instead, the local “civilians” hid German presence and altered Germans to US forces. So German artillery could be aimed in near-real time against the US soldiers.

From Wikipedia:

Vannevar Bush, head of the U.S. Office of Scientific Research and Development (OSRD) during the war, credited the proximity fuze with three significant effects.[31]

It was important in defense from Japanese Kamikaze attacks in the Pacific. Bush estimated a sevenfold increase in the effectiveness of 5-inch antiaircraft artillery with this innovation.[32]
It was an important part of the radar-controlled antiaircraft batteries that finally neutralized the German V-1 attacks on England.[32]
It was used in Europe starting in the Battle of the Bulge where it was very effective in artillery shells fired against German infantry formations, and changed the tactics of land warfare.

At first the fuzes were only used in situations where they could not be captured by the Germans. They were used in land-based artillery in the South Pacific in 1944. Also in 1944, fuzes were allocated to the British Army's Anti-Aircraft Command, that was engaged in defending Britain against the V-1 flying bomb. As most of the British heavy anti-aircraft guns were deployed in a long, thin coastal strip, dud shells fell into the sea, safely out of reach of capture. Over the course of the German V-1 campaign, the proportion of flying bombs flying through the coastal gun belt that were destroyed rose from 17% to 74%, reaching 82% during one day. A minor problem encountered by the British was that the fuses were sensitive enough to detonate the shell if it passed too close to a seagull and a number of seagull “kills” were recorded.[33]

The Pentagon refused to allow the Allied field artillery use of the fuzes in 1944, although the United States Navy fired proximity-fuzed anti-aircraft shells during the July 1943 invasion of Sicily.[34] After General Dwight D. Eisenhower demanded he be allowed to use the fuzes, 200,000 shells with VT fuzes or (code named “POZIT”[35]) were used in the Battle of the Bulge in December 1944. They made the Allied heavy artillery far more devastating, as all the shells now exploded just before hitting the ground.[36] The Germans felt safe from timed fire because they thought that the bad weather would prevent accurate observation. The effectiveness of the new VT fused shells exploding in mid-air, on exposed personnel, caused a minor mutiny when German soldiers started refusing orders to move out of their bunkers during an artillery attack. U.S. General George S. Patton said that the introduction of the proximity fuze required a full revision of the tactics of land warfare.[37]

The US Navy “allowed” their proximity fuses to be used by British coastal AAA. By that time, it was mostly the V1 that was the target.
(The USN didn’t want it reversed-engineered, so it was used only over water until late in the war, maybe the Battle of the Bulge) - Calvin Locke

I thought the first use of USN proximity fuzing was at Hurtgen Forest. And yes, the USN was extremely careful with that secret. It was a war winner.

I, too, understood that the proximity fuse was first used on land in the Battle of the Bulge. Which was a sufficiently desperate ill to have inspired desperate measures, I suspect.
The timing of the end of the war was, of course, unknown until the Battle of Berlin - and using proximity fuses to air-burst your ordinance instead of having it impact the mud first would make quite a difference. You certainly didn’t want the Germans doing it to us.