From one of the architects of the "scheme" as the Brits say. Geography of time - stop thinking of HSR as a replacement for inter-city airtravel, and think of it more along the lines of a regional development opportunity.
This guy's now done studies for the NSW government and if not for COVID, I'm sure we'd have heard something about it soon.
• Video Link
Pay particular attention around ~22-29 min in and the economic activity that HS1 generated then switch your mindset from "omg, which taxes are going to pay for this" to "u-huh, you make it work over a much longer timeframe".