I own a dozen Amazon brands that are probably largely of the kind that OP would want this to get rid of (sourced from China, not name brands by any stretch, only sell on Amazon). For the most part I would say this extension is not a great idea (obviously very biased!), since I purchase brands that have high quality products that typically have pretty poor branding/online presence that I can improve. My stuff is very frequently of the same quality (and sometimes from the same factories) as much pricier stuff but at a lower cost. To some of those suggesting you can get this stuff on Aliexpress, in some cases that is true, though of course the big benefit of buying from Amazon is that there's no risk to buying no-name stuff because if it's junk you can return it.

In any case, I gave this a try to see which of my brands it would filter out. It's weirdly inconsistent.

One of my brands was filtered out because there's no brand name at the beginning of the listing. That's just an outright bad rule, because Amazon generally decides whether or not the brand name appears first. This brand is trademarked and has Brand Registry, so it qualifies for that treatment, just not getting it right now. Also, a number of other brands without brand names did not get the same treatment (and these are very much the type of products this is designed to filter out).

On another one, it misunderstood the product model, which is at the beginning of the product name, as the brand and hid it based on that. That one was a bad one because the model is only three characters, which is extremely unlikely for a brand name.

One product I sell is a hunting accessory, so I did some searches there. It hid everything by the brand KUIU, which is a well-known and very high end hunting brand. Definitely wrong there.

So yeah, sort of an interesting idea, but the execution is pretty sloppy and the creator clearly doesn't have a full understanding of how Amazon listings work.