Parties select their representatives who run in the election.
The system basically guarantees that insiders cannot be removed.
It's the property of a candidate being affiliated with a party - an indirect part of the election - that is run by the parties rules that are generally less than entirely democratic in nature.
Liberals NDP and Greens would never form a government with the Conservatives so the liberals are effectively always in power.
Which means insiders in the liberal party are in charge and voting is partly irrelevant unless you're voting for the conservatives, but they would need an actual straight majority.
Th Bloc has 21 seats, and has had as many as 54. They would certainly ally with the conservatives. (Not the modern maple maga variety, but old school PC).