dripstone is supposed to fall and damage mobs, but it does not actually do this. instead it only damages mobs that are on top of the block it is falling on. due to this, the player can simply jump when dripstone falls on top of them, and they wont be harmed.
Steps to Reproduce:
Summon dripstone above you
/setblock ~ ~3 ~ minecraft:pointed_dripstone[vertical_direction=down]
Immediately after summoning the dripstone, jump
You will not take damage from the dripstone while you are in the air.
Confirmed for 21w06a. In addition, this also occurs with falling anvils.