Previously before the release of 1.16 to earn the serious dedication advancement a player must completely use up a diamond hoe. With the 1.16 release the diamond hoe was changed to a netherite hoe and now there is a bug where you don't have to use up the durability but you earn the advancement just by having a netherite hoe in your inventory. Here is a video showing the bug, https://youtu.be/vtZeBsVqfZ0. The video was recorded on vanilla 1.16.1.