However, for an amphibious assault, especially one against a prepared and well-fortified enemy, "not being pushed back into the sea" is by far the most important operational objective to succeed, and D-Day succeeded very much at that.
However, for an amphibious assault, especially one against a prepared and well-fortified enemy, "not being pushed back into the sea" is by far the most important operational objective to succeed, and D-Day succeeded very much at that.
I doubt it could have stopped the invasion, but would have made it much more costly.
The V2 rockets I believe did more damage to the cities in German hands than to Allied positions (including the bridge itself, which was unharmed by the attack).
Caen (port area up to 9 miles from the beach) was a D-Day objective, but depending on the area took 1 month to 3 months to capture. The Allies were slow, and the Germans knew it was a strategic location. Regardless, it just meant that the German army was destroyed around Caen, instead of elsewhere.
https://en.wikipedia.org/wiki/Battle_for_Caen
Of the 5 landing sites, Omaha Beach was the bloodiest, with Americans wading ashore into machine gun fire, killing around 2,000 Americans.
(In Italy and Holland, Americans were also mowed down as the Germans retreated.)
The most famous disastrous amphibian landings were Galipoli in WW1, where the British failed to break out of their beach heads, and also lost numerous ships to mines and shore batteries. This tarnished Winston Churchill's reputation for decades. The victory by Turkey led to its rise as a modern state.
And the US struggled with 3 landings (Anzio, etc.) in Italy in WW2 due to General Clark and his staff trying to consolidate beach heads before breaking out, allowing Germans to occupy high ground, after the landings!
https://en.wikipedia.org/wiki/Battle_of_Anzio#Breakout
Literally, the Americans would loiter on the sand instead of sending a dozen troops to secure roads and hills before the Germans arrived with artillery.
The US had phenomenal leaders in the Pacific War, but Italy was a total failure in multiple dimensions. Historians today just laugh at our role in Italy - it was that bad.
(The British had the weird problem that upon reaching the beach, soldiers would sit down and start making tea, even under fire.)