IMO Chrystia Freeland would be a great pick for the country. She was firm and capable during the NAFTA/USMCA renegotiations, and seems to have stood up against political games from the current administration to her eventual detriment of losing her cabinet position.
Marc Carney certainly has appeal, but I can't help but see him as Ignatief 2.0 and that didn't go well with many Canadians.
Chrystia Freeland was too close to Trudeau for too long (their fallout notwithstanding) to be perceived as anything than Trudeau 2.0
Marc Carney is a (two time!) head of a central bank - he hasn't got a chance in the current anti-elite climate.
Then again I'm on the fence on Freeland, as are most of my circle as anecdotal as that is. Our issues with Trudeau don't completely extend to her, and if she differentiates herself well enough along a few lines she might get more support than traditionally expected from a Trudeau cabinet member.
Or maybe that's wishful thinking. Our alternatives haven't done much in the way of proposing a viable alternative path and have focused almost explicitly on criticizing Trudeau and the parties actions. Its appealing to the "fuck trudeau" flag flyers but I do wonder if centrists will find the CPC appealing without a change in direction and messaging now Trudeau is leaving.
Both the opposition Conservatives and the supporting NDP parties (NDP in particular was holding up the Liberal Minority Govt) have been planning non-confidence motions this month that would result in a new election.
There was no path to victory for Trudeau after that, so the next best move is to resign and hope the liberals can pick a new leader before the next electoral cycle is too far along and avoid the issue the Democrats had by rushing to select a replacement candidate and alienating some portion of voters by doing so.