The 747 and like jets made air travel affordable and now air travel is cheaper than by boat/rail over long distances (for people, taking into account food and lodging). If you need to attend a wedding more than a few hundred km away, you are going to consider flying. But high speed rail networks in many countries (uk, france) are either extreemly expensive or massively subsidized. All i see are suited office workers heading to jobs in downtown cores.
The carbon footprint of high speed rail, while not as bad as air, also remains much higher than other ground options. Speed always comes at some price.