Mobile phones (as well as smartphones) do come with a genuine charger no doubt. When I say genuine, I mean chargers passing minimum device specification.
But what happens when such charger gets burnt or damaged by whatever means? You try to get another I presume.
Most stores do sell replacement chargers recommended by the device manufacturers, but what if you're traveling and there is no store nearby? Or you want a car charger and you're buying from the road side?

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