>>510692191they have to because the thing goes inside
that always makes the thing that te thing goes inside into the reciever
and the reciever is always passive, it always waits for the thing to enter
the reciever is not a transmitter
transmitters and recievers are two inherently different categories of devices
both can function without the other but without the other no greater function can be taken from the existence of each of the two in the first place
i.e. if humans stop breeding its time for a new species