OT, but when did actual plot details of fictional universes become business decisions? I can understand the business side setting constraints for plot writers

OT, but when did actual plot details of fictional universes become business decisions? I can understand the business side setting constraints for plot writers to include or exclude certain characters (to tie-in with merchandise and promo campaigns) and maintain reputation, family-friendliness, political orientation, etc. But I always assumed that apart from that stuff, the business side would be mostly uninterested in the storytelling details. But "cinematic universes" feel like something different. The fictional world and its continuity itself becomes a business asset. Suddenly writers are implementing executive decisions how the world should develop. On the one hand, it feels a bit like devaluation of the craft. In another context, some space time anomaly that ties different timelines together could make an interesting story, but here it feels functional. On the other hand, I wonder why they even bother with an in-universe explanation. They could have simply announced that the sequel trilogy is noncanon, or made the next part into a reboot or something like that. Are they so worried that parts of the fandom will drop off if the continuity is ever interrupted? (Ignoring how many times things were already retconned) I think that's what feels weird about cinematic universes for me. They feel like someone is trying to build a real-world business empire inside a fictional universe.