In NZ we have a series that @jon_sullivan created for interactions, and they used to list mostly together. Now there are a lot more similarly named fields, they are scattered through a number of pages of results.
The observation fields page is one of the older areas of the website in need of a design update. Being able to click to sort by name and number of uses seems like a no-brainer. I updated the feature request title to match that, but feel free to edit.
Sorry for the late follow-up here (thanks @jwidness) but we added sort functionality for both Name and Date Added (click the top of each column to sort by that attribute):