Originally Posted by jackal

A missing cable in Europe is a much bigger deal, because most/all Level 2 chargers in Europe require you to supply your own cable and plug it into a port on the charger (which arguably makes more sense, but that's a different story). In the US, public Level 2 (and Level 3) chargers come with cables attached, so you don't need to carry a cable around with you to use them. In the US, mobile chargers are mostly only useful for plugging into 120V outlets (which might add at most ~10% overnight) or, in a pinch (in an area with few J1772 chargers) plugging into a NEMA 14-50 outlet at like an RV park or (depending on when the house was constructed) a dryer plug, but most people renting cars aren't going to be doing much of that.

Also, at least when it comes to Tesla, for cars manufactured after around May of 2022, the cars don't even come with mobile chargers, so the lack of one really isn't a case of a "missing" cable. (Not sure what the status of included mobile chargers for other brands is.)