US story here. Here, an "extension cord" is usually a two prong plug, some feet of wire, and a three-outlet socket made with a tough and slightly rubbery plastic. They are useful and safe.
A couple decades ago, I bought one at the "dollar store". This one did not have the tough and rubbery outlet. It was thin and brittle plastic. After I hit the end on the floor, the outlet broke apart, exposing the conductors. This could certainly have started a fire.
And yet, there was a sticker on it "claiming" UL compliance.