Quote from alleywig on 2016/04/04, 03:40

In 1.9 the sword swipe attack was aimed to deal damage to multiple enemies, however something prevents that from happening on our server. This leads to many spammed attacks by swords and the new mending enchant becomes useless, as it wont be able to keep up the repairing of the sword because each attack now causes more durability loss than in 1.8. Just to be clear, if each enemy were to be hit by 3 attacks versus 3 attacks per 3 enemies, it adds up quickly- without the mending enchant. The swipe attack was created to counteract that increased durability loss and make mending a good option.

Users can gain experience to repair through trading and ore, but if they are doing some heavy exploring or at a mob farm, they'll find their swords depleting faster than intended.

The other option is to kill with a bow and arrow, as this type of action doesn't produce more durability loss than in the previous version. However, arrows can miss-fire or miss altogether, making the durability drop about as quickly as the sword if not careful.

Hope this helps anyone :)