Every category page and every search-term page shows its top 10 apps to everybody, signed in or not. That part is not going behind anything — those pages are how most people find this site in the first place.
Seeing the whole list, with how far each app moved, is what uses an unlock. Signed out you get one, ever. A free account gets 10 a day, and Pro has no cap.
A page you have already opened stays open for the rest of the day, so re-sorting it or coming back to it later does not use a second unlock.
Unlike a report, showing you the whole list costs us almost nothing — the data is already stored and nothing is worked out on the spot. The cap is there so Pro has something to offer, not to cover a bill, and that is worth saying plainly rather than dressing up as a cost.