They sure do, and they have a system to flood their shop with fake positive reviews and the money to advertise harder than the little shops. I used to design jewellery and used a service to 3d print and cast them in precious metals to order, and found some of my designs on Ali express. Jokes on them, they weren't selling. The only thing from my shop that sold were the handmade fine silver chains lol.

My partner and I also had some funny sticker designs on redbubble and the instant one of them started doing well we would find the design screenshot, cropped slightly, and uploaded at a lower resolution. And there would be like 20 of those within a day for the same design until it stopped selling. We didn't bother uploading anything again after that happened a few times.