I get what you're saying, in effect a chicken and egg paradox with cars vs public transit. I think that's a fair argument when it comes to commuter transit, but ultimately the horses have already left the barn. The vast majority of the country is now set up for car dependency (except in about 4 cities), and considering the climate it's going to be almost impossible to compel our fat aging population to stand in -20 degree weather waiting for a bus or train to get groceries unless you're 25 years old and have an abundance of time and energy.

To your other point, the hub and spoke trigonometry doesn't apply to Canada, the population's not laid out in that way. It's already for the most part a linear layout produced by a set of parallel competing rail lines running a couple hundred km from the US border. The rail was the factor that made the majority of the country's settlements. In America or other countries I think your point is absolutely fair though, because there's actually vertical girth to the nation that makes an actual hub and spoke system feasible.

Ultimately though I just don't believe anyone would use a train to spend 15-20 hours to get from Toronto to Calgary on high speed rail. Or even 4-6 hours to get from Vancouver to Calgary (likely not possible anyway considering the terrain). They're going to fly.

And almost no one is going to take a train from Regina to Winnipeg when they absolutely need a car at their destination to do anything anyway. Even the proposition of connecting Calgary to Edmonton is massively ridiculed because people understand how exceptionally light-weight your trip must be to forgo a vehicle at either end for the sake of saving maybe an hour by taking a train. It just seems silly considering the realities.