Totems arent used when you die if they are in the head slot, this dosent affect almost anyone in the minecraft community, mostly just personally bothers me.
Steps to reproduce:
1.17 and up:
Run the command "/item replace entity @s armor.head with minecraft:totem_of_undying"
without quotes
1.16.5 and below
Run the command "/replaceitem entity @s slot.armor.head minecraft:totem_of_undying"
without quotes
Edit: I am aware that after snapshot 24w37a it states that you have to hold it for it to activate, this website dosen't let me select versions older than 1.21.3
Totems use the
death_protection
component.https://www.minecraft.net/en-us/article/minecraft-snapshot-24w37a
Equipped != held.