People like to hide behind committee or group decision. Ownership and accountability is diluted. If the project succeeds, you can claim a win as the committee member. If the project fails, you can hide behind the group decision.
It takes courage to take ownership and decide on your own and make things happen. You have no one to hide behind. But you also have big motivation to make it succeed.
Taking ownership does not mean being a dictator. You need to consider all the inputs you can. But the final decision should not be done by agreement. People should own their decision, even if they are unpopular, if they think they are correct.