I think kyle44 nailed when it comes to this tournament especially with North American teams it absolutely matters how much they care. I think the game against Slovakia was critical to establish this team's identity. It was a very sloppy game but we just kept coming back. Now it appears we've ironed out the sloppiness, so we're just a good team. I wonder if any of the 2010-14 or 2018 team Canada's would have won that game.
There's something to that, but I think a big factor is chemistry. Canada has kept pretty much the same lines throughout this tournament, and they've worked for the most part throughout. The pairings haven't changed much either. There are teams like the team last year where I think they care but it just isn't working. You're right to highlight some of the teams early in this decade where the effort wasn't there.
One thing I noticed about this team is how much ice this team covers. The defencemen are all (except Stecher) mobile, are good at long, stretch passes, and tall in size. The system they play just suffocates oppositions into turnovers. It's interesting to see how Canada changed from a hard-hitting system to a good skating, suffocating team.
Vigneault has done a good job with systems, but yes a big thing is that Canada selected appropriate defencemen. There isn't a Demers or Edmundson this year to muck things up because he's so ill suited to the larger ice surface. Heady defencemen with good skating, particularly young defencemen, should be Canada's targets for this tournament. It's good to get these guys reps in the (hopeful) event that there is a bigger tournament waiting somewhere down the line.
Regarding the hitting, that is a part of Canada's game that is missing and probably should be brought back but it's out of style at the moment. You can see flashes in guys like Dubois or Mantha, but they would have been physical monsters had they come up 15-20 years ago. One good element of Canada's game that has been big in this tournament is that the team has been tenacious when trailing. In the Summit Series it was noted that the opposition found it odd that the Canadians kept playing very hard even when the game seemed over. That is still there at least this year.