> I assume that anything I buy in a store for general use is suitable for general use unless specified otherwise.
That's not a safe thing to assume, or at least, the way it's specified otherwise is with a current rating.
I had to work at it a bit to find one on Amazon; a search for "lamp extension cord" led me to the sort of thing I'm talking about[0]. These do show up in retail stores, especially low-cost stores (e.g. dollar stores, but I wouldn't be shocked to find one at a Walmart). This cord is rated for 5A. A standard American household breaker is rated for 15A (and it's possible to encounter 20A). Plugging in a hair dryer, toaster oven, or space heater with this cord is a fire hazard.
I note the plug shown in a photo says 10A while the description says 5A. I don't know which is true.
So yes, should, because you can walk out of a retail store with a combination of electrical devices that will burn your house down when used in a way that would appear safe without that knowledge.
I live in Europe, and we have (usually) sensible consumer safety rules for everything.
So, here's my equivalent: https://www.action.com/de-de/p/2520398/pro-max-verlangerungs...
Germany's mains is 230 volts, so the 3680 watt limit implies 16 amps.
Other than hard-wired things like the oven and heat pump, I'm not sure my house has even one single item that draws 3.7 kW…
That's not equivalent because German household breakers are typically 13A, which is less than the 16A that extension cord is rated for. A 2.5A rated Europlug cord[0] is the closest equivalent, but safety standards help there too. Higher-current devices use Schuko, which will not readily plug in to Europlug.
I found an easy way to create an unsafe combination on German Amazon: a Europlug to IEC C8 cord into a C8 to C13 adapter. That's much harder to do by accident than the American version.