Make a board, drop the link in the group chat. Anyone who opens it can add ideas, vote on them and argue in the comments, without downloading anything or making an account.
Nothing is required but the name. A trip with no place and no dates yet is usually the point.
A chat loses the decision three scrolls up.
A board keeps every idea in one place, shows what the group actually wants, and lets the quiet ones vote instead of having to argue.
Nobody has to be the planner.