Summary:
When the player breaks a campfire, it drops 2 charcoal, which is intentional per MC-141909. However, if a piston or an explosion breaks a campfire, it only drops 1 charcoal.

Steps to Reproduce:

1. Place a piston facing sideways
2. Place a campfire in front of the piston
3. Activate the piston
4. Pick up the charcoal
5. Place another campfire
6. Place TNT nearby
7. Activate the TNT
8. Pick up the charcoal

Observed Results:
Campfires drop 1 charcoal when broken by a piston or an explosion.

Expected Results:
Campfires should drop 2 charcoal when broken by a piston or an explosion.

Video:
Minecraft 2021-08-23 11-59-05.mp4