Those are private label brands where the US or EU owners look for ready made low cost products within a category across different Chinese factories and slap their logo on top. Like SEO they game the product search engine and listings on Amazon to appear on the first search result pages, knowing that most impulse buyers don't have much patience.
The factories usually ship directly to Amazon warehouses and it is also fulfilled by Amazon (FBA).
The factories usually ship directly to Amazon warehouses and it is also fulfilled by Amazon (FBA).