Stepping down can sometimes be the real power move in politics, and for a politician that had quite few power moves for such a long tenure, this was one of Trudeau's.
And between the potential leaders, Carney is the only one that has a clear vision for the future on top of a plan to make it happen. While I don't agree with half of the stuff he's about, that's a million times better than a man more interested in causing division amongst Canadians when faced with an external threat, spineless coward that flip flops depending on what he things gets him political points, or people who have zero chance of gaining enough seats to make a serious change.