DC fast chargers, like superchargers, have attached cables. They kind of have to, nobody's going to carry around a 300 amp cable. They're heavy and bulky.
AC chargers, which are in the 10 to 32 amp range, sometimes have attached cables. The ones that don't just have a type 2 port, so you need your own type 2 cable.
They're a handy thing to have sometimes. You can always get one later if you need it.