And it's not just Westjet: Air Canada also made a heavy bet on the 737MAX, so AC wasn't able to take full advantage of the other's misfortune for a lot of medium-distance destinations.
I was surprised what I paid for flights YYZ-CDG next month. I'm paying more for flights in November (dead-time) than I did for the peak of summer, but that's because I booked the latter pre-grounding.