Gotta build another pipeline halfway across the country before that 😉

Calgary-Edmonton-Vancouver can use the Southern pass past Crowsnest where there is already a railroad.

Flying is subsidised in nearly every country world-wide. Kerosene is either tax exempt or there's a reduced tax. If the tax were to be raised and the money put into trains and public transport, it could very well be affordable. And if building oil pipelines from Calgary all the way to the coast is possible, building high-speed rail for sure is.

Regarding travel time, Vancouver to Crowsnest Pass is currently ~1000km. At 200-250km/h that's 4-5 hours. Add a few stops of 5-10 minutes each (let's say 6) you add about an hour. That's not crazy at all. From Crowsnest to Calgary it's about 200km so you'll be there in an hour or less. It it's a bullet train and the terrain is good, that's less. Btw, bullet trains operate at 320km/h . With proper adjustments to the track, that would also reduce journey time.

While the flight from Vancouver to Calgary is 1.5h, you have to factor in getting there and waiting on the flight. If you follow the guidelines to be there 2h before the flight, that's 3.5h and maybe 0.5h to get there + 0.5h to get off the plane, grab your stuff, and get into the city center. That's ~4.5h. Compared to 6h on the train. On the train you have leg room, stow room, you can walk around, stretch your legs, buy something to eat in the concession cabin, you'd have a good internet connection, and to top it off, you could do the journey at night in a sleeper cabin to wake up in Calgary or Edmonton.

I'd much rather put my legs up in a train than fight through whatever city traffic there is, worry about navigation, breaking down in the middle of nowhere, and pollute the environment while doing it. Once you grow up around functional public transport, it's hard to look back at cars and go "I want that, I want to be in it, I want to be around it".