The people who make these products have to spend millions and millions of dollars setting up factories, hiring people, putting things into production, etc. But somehow they don't have a budget for a bilingual college student intern to translate a bunch of copy to English better than "using this product will bring a great joy." Why? I would be super interested in some journalist figuring out why this happens.
Of course, there's always the viewpoint of "why would they need to translate better? It's just money that they don't need to spend, and this works for their business." So I will make a super strong claim: ChatGPT can now do nearly perfect mass translations of this stuff for free, in theory simultaneously increasing translation quality and reducing costs. Despite this, for whatever reason, I predict that the average translation quality on Amazon won't improve within the next few years.
Anyone want to take the other side of that bet?