How did it take three hours from deplaning the first aircraft to departure if DL quickly found another A330 at SEA, towed it to the gate, etc.?

From SEA, I'm surprised that the FAs who opted not to fly your flight weren't put onto other flights where they still would have been legal rather than just being allowed to go home. Plus, many FAs seem to like to bid for international routes around holidays because those with less seniority can get interesting trips then to places where they otherwise wouldn't have a chance.