Thanks David, and I hope to hear more from you. I find the measurement problem most intriguing and continue to try to follow what is new in explaining this. Most scientists would agree with you that consciousness has nothing to do with it. Henry Stapp is one current one who disagrees and has developed quite a bit on this following on von Neuman and Eugene Wigner (who changed his mind about consciousness in measurement.) As for decoherence, some certainly treat this as definitive, but I asked AI and here is what it said:

"No, decoherence is not considered a fully established solution to the measurement problem in quantum mechanics; while it provides a significant explanation for the transition from quantum to classical behavior by describing how a system loses coherence due to environmental interactions, it does not definitively address the fundamental question of wave function collapse and the nature of measurement itself, leaving room for ongoing debate and interpretation."

Curious your thoughts on this.