Importance of teammates
Arguably, what really led to Hamilton losing the race was not having a teammate in a relevant position. If Bottas had been in the top 4 and had pitted around the same time as Hamilton, Ferrari would have had to pit Vettel in response. As it is, Vettel was under no real pressure and could stay out for longer in the hope of a safety car / VSC. Yes, he got lucky, but the opportunity had been set up by qualifying and Bottas being unable to overtake and catch up.
I'm not actually criticising Bottas. Crashes happen in qualifying, it's when drivers really push the limits. As long as it doesn't happen too often it's not a big deal. And he wasn't the only one struggling to overtake in the race. I'm hoping the lack of overtaking was due to Melbourne being a street circuit and that other tracks will give more exciting racing. We'll just have to wait & see.