Comment by quantadev
Isn't it true that in key exchange entanglement isn't used in any way shape or form for sending data, but only in making a determination that there was no eavesdropping on the transmission, because any eavesdropper would collapse the wave function.
So like you said, entanglement can't be used to send information, but it can be used to detect if the transmission was secure (I think)
There are many protocols for quantum key distribution/exchange so it's hard to answer fully without knowing which one you're talking about. That said their are protocols, like the one invented by Artur Ekert in 1991, which use entanglement in an essential way to transmit the key. Even in the absence of an evesdropper the protocol will not work without entanglement. It escapes the no-communication theorem by also requiring some classical communication.