Equipment sharpness and mana does not go down (1.16.5 - 2.3.2.2)
Equipment sharpness does not seem to go down, no matter how much the item is used. This also applies to equipment that uses mana. Strangely enough, crafted equipment using parts from creative mode do not have this issue.
To replicate: Start a new world in survival, collect or craft some parts fairly without getting them from creative mode, and craft a piece of equipment on an equipment forge. Upon using the newly crafted equipment and you will see that the sharpness value never goes down.