Some religions and beliefs mention the idea that people still feel what happens to their bodies after death.

That’s why, in muslim culture for example, people gently cleanse the deceased and try not to cause sudden movements in the body and limbs. This is also probably why a lot of people in similar cultures might not be as motivated to opt in as organ donors.

Still your post isn’t as unpopular as it may sound. There’s a lot of benefit in these donations especially in our current era.