Use one shared plan that everyone can edit, not a message, a PDF or a screenshot. Read-only itineraries go stale the first time something changes, and then half the group is following an old version.
Anything posted in a chat scrolls away within hours. By the time the trip starts, the current plan and four superseded versions are all still sitting in the thread, and nobody knows which is which.
It's accurate exactly once. The first restaurant change makes it wrong, and the person holding the file becomes a bottleneck for every update — which is how one person ends up doing all the planning.
This is what bothways is built for: one trip, one link, and everyone adds their own flights, spots and plans directly instead of routing everything through the organiser.