This is an overly dramatic perspective that is likely informed too heavily from popular media, it's not really accurate.

First off, the landings on D-Day occurred at multiple locations, and many of them went off fairly well. At Gold, Juno, and Sword beaches, for example, there were fewer than a thousand allied casualties at each location (keeping in mind that tracks both killed and wounded). Which isn't to say those landings were cake walks, they were still difficult fighting, but they were very successful landings with modest casualties. Substantially, support by DD amphibious tanks was helpful in each case.

In the public mind though it's the story of Utah and Omaha beaches which has become the cultural recollection of D-Day. Hard fought landings, tanks floundering in the channel, seemingly long odds, high casualties, etc. Even for Utah and Omaha these stories are a bit overwrought. While the first wave had extreme difficulties and experienced heavy casualties they were still able to achieve many objectives, and subsequent waves improved the situation. At both beaches overall casualties were far lower than 1 in 10, so it was far from a suicide mission.

At Utah beach, for example, the first troops arrived at 6:30 AM, within just the first 15 minutes there had already been 3 waves landed including over two dozen DD tanks, 16 M4 Shermans, and 8 M4 bulldozer tanks. Even at Omaha well over a dozen tanks made it to shore during the initial wave, many more landed afterward, and were a key component of the fighting there.

As mentioned above, each landing was intended to be well supported from the first wave onward with armor, and at many beaches that was the case. Even at beaches where it didn't work as well armor and artillery support was still present, and a major factor in turning the tide of battle. So it was anything but a matter of just throwing men into the maw of the Atlantic Wall and hoping for the best, it was a well put together combined arms assault that in many cases went off well.

A lot of the popular culture coverage of D-Day hyper focuses on the most dramatic aspects of the assault. The first wave assaults on the most hard won beaches. And the most desperate struggles of specific units on those beaches. And they consistently omit many aspects that balanced that sense of desperation. At every beach just about every soldier could see and hear the tanks on their side working against the enemy defenses, and yet that's something that almost always seems to be just off-screen in movies and television depictions.

Make no mistake, for many soldiers in the D-Day assault it was a nightmare, and many lost their lives, but that's a minority story in the broad scope of the landings. Many landings went much smoother, and the later waves of landings were consistently better supported and experienced lower casualties. Over 150,000 soldiers landed on the beaches and lived with most assault objectives were achieved quickly and completely (within a matter of only a few hours of landing). But these aspects of the landing don't make for good media. The most dramatic, most desperate, and bloodiest fighting of the landings is certainly a valid part of the story of D-Day, but it's not the whole story.