Raised this first for plasma-discover (https://invent.kde.org/plasma/discover/-/issues/18), but they're saying it's using the appstream and suggested to raise a ticket here.

Here's the simple example - I tried to search for "konqueror" I can only find it at ~ hundred position from the top, when the results are sorted by relevance (I think this is what plasma-discover guys are using now by default)