Decoherence and Wave collapse are not the same thing. Wave collapse is when a particle hits a physical object and dead stops. Decoherence is a particle being measured in flight and allowed to continue moving on its path. Decoherence now means all quantum particles are not physical/real ..they are condensed wave packets that give the appearance they are physical/real after a decoherence event.
Coherence is the state a wave has to be in to perform quantum weirdness events. Coherence is orderly waves. Coherence is the world of the unobservable.
Did we overlook one crucial detail about duality? Duality is not a physical/wave object. It is never physical, it is either waves or condensed wave packets (decoherence).