Electronics can indeed be cheap. There is, of course, some degree of electronics regulation because all these e-bike are fine being recharged. But that could be only constant voltage with no current limit. A high internal resistance cell would overheat possibly to the level of combustion.
This is where the other type of regulation comes in. There are regulatory authorities tasked with protecting consumers from being sold goods of dubious/dangerous quality. They require government legislation to act against these shoddy goods. So governments need to get their fingers out and pass legislation to ensure the unaware consumer has some sort of protection.