The New York Times did some decent reporting into the pseudo-brands which comes closer to answering the question in the title: having a registered trademark unlocks a lot of on-platform seller tools (predictive analytics, early review program, etc.), and the easiest path to a trademark is to have an utterly unique, nonsense name. Some Chinese municipalities were also offering cash incentives for citizens who obtained foreign intellectual property registrations, further exacerbating the problem.
Full article at https://www.nytimes.com/2020/02/11/style/amazon-trademark-co...