The SL Marketplace is the last bastion of a free market in SL, as every other type of shopping event or venue is selective: resident group-run events which are highly restrictive as to whom they will admit; Shop 'n Hop curated by the Moles which is also highly selective; other Linden/Mole opportunities like Welcome Area displays or shops, birthday and other celebrations, and the Bellisseria Commercial stores currently no longer issued and in extremely limited supply. The MP represents the last free and open place where especially a new person, or someone just beginning to create with either inworld or external tools, does not even need to own or rent land, but can upload their creations and start selling them immediately to those who find them. They should indeed be findable without suppression in search results because they are arbitarily blocked.
Any type of mechanism that enables a shopper to subjectively block disliked merchants for any reason or no reason will in the SL context be subject to flash-mobbing, web-brigading, or just the fickleness of fate and fashion. Inevitably, such collective, accumulated actions, even if perceived to be made individually of free will by shoppers, will indeed affect search outcomes to one extent or another. Some Canny proposals explicitly demand that any merchants blocked by residents should in fact be punished with degraded search results as occurs on X (Twitter) platforms or social media systems where blocked accounts begun to feel a "shadow ban" and a failure to be found normally. Yet shopping sites such as Amazon do not enable "block merchants" except for very precisely-defined customers in government subject to procurement rules; Google expects that the user uses a variety of search terms and Boolean queries and revisions to refine results and also has no function "block merchants I dislike".
The current features of search by rating and especially by category, price, permissions, etc. are certainly sufficient. And indeed anyone can search directly for the name of a specific merchant under the "Merchants" tab. They can also refine with categories on the side bar and adjust the maturity rating. (At least one Canny proposal seems to have emerged from the unwillingness to uncheck "Adult" for literally "cleaner" results).
Whatever "merging" and "tracking" these "block" proposals have garnered from the Lindens -- mainly due to antagonism at perceived as "AI slop" -- i.e. any advertising or product using AI -- has not led to implementation in two years and is not likely to given the Lindens business model of earning commissions from each sale on the MP.
There are now third-party sites like SecondPixel and Primfeed that explicity either ban AI or require that it be labelled and these could be used handily in lieu of the MP for the minority of those with the anti-AI sentiment. The MP must remain open and free enterprise must prevail there, where "a willing seller meets a willing buyer," regardless if it is "tacky" or "a scam" -- or SL will have essentially moved to a licensed content creator system which they have never done in 23 years. If there is a concern about copyright violations, either an AR can be filed or the IP owner can file a DMCA takedown; LL cannot be in the business of demanding price ceilings or quality control they have neither the resources or the general population's consent to police. The concept of "scamming" is hard to define fairly and difficult to adjudicate; those bothered by ridiculous-high priced scripts need not buy them, and can search with filters of under 1000L to remove them from view. If the demand is that AI must be marked and identified, either voluntarily or automatically, it must be realized that this will be expensive and time-consuming to code and test and hardly solve the problem of "unwanted" content in search results for everyone.