Sometimes I go to edit a card and see that a draft already exists that someone else created days, weeks, or months ago. Without manually comparing the draft to the published version, I have no way to know what changes were actually made. A little toggle that can highlight changes, similar to the feature that shows what changed between different versions of the published card, would be much quicker than either manually reviewing or contacting the draft author to ask if they remember what edits they made (especially for old drafts they may not remember details on).

Sometimes people also just accidentally click the edit button and then back out of the page without actually deleting the draft that it automatically creates when you begin editing a card. So this leaves a “draft” open indefinitely that is 100% identical to the published card. 

This feature could also be useful just to help me verify as I’m working on a draft whether I’ve made all the changes I intended to, if I forgot to remove old info that’s no longer relevant, etc.