I get what you are saying that it works similar to that on other platforms like Instagram or Facebook search where they show you more posts similar to topics you liked and less of the content that you marked not interested. But the thing is, in order to do any of that you have to get matches in the first place.
And Fiverr's search is much better since you put the search tags yourself and the relevant profiles show up and you can choose from them. From what you are telling me it seems like the AI chooses random tags from your description and tries to match sellers out of the one category you chose, hence the bad matches. e.g. graphic design means manga artist, T-shirt design, UI/UX or any other sub-category you get when you make a gig on that category.
From the links that you have provided, it just seems like fiverr is going the paid promotion road on top of all the commission it earns from sales. And what is this "high quality" sellers? From what I understand, if you are high quality, your level will rise up since you are completing the requirements automatically if you are completing the orders. So basically you ARE matching the briefs only to top rated sellers and pro/ paid sellers.