I think you're definitely on to something here. Planning makes me anxious and I would prefer to wave a magic wand and have it done for me. I think there needs to be a way of including other people in the planning process though. Maybe this could be a conversational ai app in the personal assistant category.
For example, if I need a dinner reservation made, I want to be able to say "make a dinner reservation for 2 people and run it by my wife". The app should be able to follow up (eg. "do you care what time or day this week?"). Then it should give my wife two or three options and ask me to confirm.