I use F-Droid. It is the only "app store" I use. I love it. I greatly appreciate the new interface.
However, one thing stands out to me. When I look at the "categories" page, I see that all the names of the apps start with "A" or a number. This is because apps are simply alphabetized. While alphabetiztion helps people find what they are looking for in a short list, this isn't very useful for long lists. Especially on the categories page, where we only show a few apps from each category. It would be much more useful to show the most downloaded apps of each category. We could also rank them by most recently updated and factor that in to how we display them. We could also place any new apps prominently in each category.
Another time when relevance could come into play is when you search. Search for "f-droid", you will get almost all the apps if not all of them. You will then have to scroll through all of them to find "F-Droid". I know this is an extreme example. Could we sort the apps in search first by relevance? Maybe show the ones that have the keyword in their name first, then show the ones that have the keyword in their descriptions? And maybe we could also sort them by number of times downloaded?