All I can say is that as I've aged and experienced some health issues that make mid to long-haul flying unbearable in the tightest economy seats, I've made some conscious rules-of-thumb:
- nothing below 30" pitch for up to 4.5 hours; will choose something with extra legroom if it is reasonably priced.
- 5 - 6 hours must have some sort of extra legroom.
- long-haul is premium economy or better.

So, won't ever be flying in Westjet's back-of-the-bus seats.

I wonder though if Canada's aging demographics, particularly those with $ for travel, are a factor in the article referenced above.