Durability mechanic
Summary
A new mechanic called "Durability" that modifies the durability of the item held in the hand of a player. (add and remove fixed numbers and percentages of durability)
Usage
Creating NPCs that repair items, making players use skills in sacrifice of durability, create enchants that restore durability when fighting / breaking blocks
Value
Can never go wrong with more mechanics, gives more variety to NPCs, skillmechanics and a ton more
Priority
Not too important, would be incredibly useful for some people, but useless for others.
Implementation
I recently used something similar to this and it worked fine https://www.spigotmc.org/threads/tutorial-1-18-manually-reducing-item-durability.539264/