Firstly, countries such as Sweden, Finland and Norway also have low densities, not all of Europe is is the Rhine valley or Southern England. secondly, most Canadians live in a relatively small part of it anyway, meaning that densities are similar to modestly populated parts of Europe in a lot of Ontario and Quebec. Thirdly, Australia has much more electrification and much more well used passenger rail in spite of being even sparser. Sure, the distance between Perth and Sydney is impractical for high frequency rail, but that doesn’t mean that there can’t be climate friendly, efficient transport in the dense areas