I exactly know how you feel. I have been doing private label for more than 10 years now. However, there has recently been an epidemic of Chinese sellers (aggressive replicators who will copy your products and do anything to sabotage you), who are clearly getting desperate.
In the past, I managed to launch a product and then sell it as my holy grail for many years undetected and make a lot of money.
Now, every time I launch a well-researched new product (I design it from scratch and there are no similar products / not a generic product), within less than 3 months, swarms of just launched Chinese sellers start popping up with their exactly replicated listings, with the only exception being a brand name consisting a random mixture of letters, all with walls of 5 star reviews, photos of celebrities in their reviewer profile, names such as “Maggy Patrick”. Of course, my listings start getting bombarded with negative reviews, they run aggressive PPC and subject me to black hat attacks.
This used to be rare, now it is happening to everyone.
Please don’t try to equal them. These “replicators”, as I call them are buying their reviews. Their listings will always pop up with 5 star reviews left within days of launch. And yes, you can expect black hat tactics to damage the standing of your own listing, so they can outsell you.
My advice is that you never launch a product without having a carefully planned strategy how to fight this abuse. You need to have an Amazon Brand Registry for the brand. And not just for the brand, trademark the name of the pattern / design or the accessories and then use it in the product’s title or description. Once they replicate your product, you can be guaranteed they will unknowingly copy the name of the trademarked term used in your description.
Use Amazon Vine to get reviews. Then, use trademark reports / legal action to get rid of infringing listings that copy your products and purchase fake reviews.
Trust me, I know how badly it feels when they have walls of 5 star reviews within a week, when you had to wait for yours and they are not all 5 stars.