Based off of this question, "What is the role of different damage types in D&D 5e?"
That question dealt with the difference between types of damage such as fire, cold, and lightning, and what the point of using a spell that deals a certain damage is when another spell of a different element deals more damage. My question is specifically about weapons. In 5e, unless the weapon is magical, it deals either bludgeoning, slashing, or piercing damage. Is there ever a situation in which the type of damage a weapon deals has some sort of mechanical benefit? I can't remember seeing a monster in the Monster Manual that is weak to one type of damage but not another. Most entries that mention any of those types of damage typically say that the monster resists "bludgeoning, piercing, and slashing from non-magical weapons," or something to that effect; there's no entries I can remember that specifically mention one type but not the others. Are there any monsters that are vulnerable or resistant to one of those damage types but not the other two? Or spells, such as walls, that can be countered more effectively with one rather than the other?