Blue Whales have thick skin, often several inches or more thick, in fact. Their skin is so thick that most marine predators don't even consider attacking a grown whale, which is also the largest known animal to have ever graced this Earth.
On the opposite end, I love peaches, with their soft, fuzzy skin that sometimes you can peel off just by pushing your thumb against the side. You can cut into it with a butter knife, and it was uniquely designed by nature over hundreds of millennia to bear delicious, fruit sought by the tiniest of creatures to the largest land animals.
And each has a purpose. But we can likely agree, durability matters. A peach grows and dies in a season, while a blue whale gets close to becoming a centurion, like the most blessed amongst humans.
To survive until ingestion, one needn't have thick skin - thinner skin is your ideal. If your rotting softens the ground for a seed of you to take root, then rot you must. If getting eaten gets you closer to reproduction, go do it for in this case life is death.
For others, though, life is more. The blue whales traverse all oceans of the world, save the Artic Sea. At 300,000 pounds and pushing 25 meters long, they majestically swim the Earth with orcas and humans as their only natural predators.
And, while humans managed to wipe out 99% of the population in a few decades about a hundred years ago as whaling exploded and then conservation efforts first began, Blue Whales have been on Earth for over 4.5 million years.
Thick skin helped Blue Whales survive from a moment in time when hominids were a diverse species of fur covered mammals, 2 million years before humans could create fire, until today.
Thick skin has done quite well for them. Methinks it may do well for others, as well.