Canadian Politics Today

It could be the fact that we have so few viable national parties.

For example, in Germany, they have over half a dozen parties currently holding multiple seats. This means both more fragmentation in parliament, and more opportunity to select allies.

In Canada, we usually end up with 3 national parties with a significant presence in parliament, and 2 parties seem to dominate. It makes it trickier to put together a coalition, since you have fewer possible alliances, and any team-up will involve a huge party combined with a smaller party (most likely a Liberal/NDP team up). You'd never have a Liberal/Conservative coalition since both parties are viable contenders to win majorities in future elections. And you won't have a Conservative/NDP coalition because the parties are too divided ideologically.

That’s due to FPTP.

With a system that better represents the electorate, despite getting more popular vote, the parties on the left side of the spectrum would likely rule as a coalition.   

In that system, I think there would have been much less incentive for Trudeau to call an election as a majority government by 1 party would be even less likely.   However, in other circumstances, maybe there would be more elections if the coalitions couldn’t govern together.

But, looking at New Zealand, they have an election every 3 years.  So this notion that other systems produce unstable governments is probably people cherry picking the countries where this happens and saying “see?  This is what electoral reform would do”.