If trains are so inconvenient, why have Europeans been able to make a go with them? From what I have heard the European passenger train system is quite good. Passenger service in NA is a disaster because governments are in thrall to the automotive industry. In fact, all levels of government have been in thrall to the corporate sector for years and that servitude has been a disaster for the creation and maintenance of national and regional infrastructure.
Europe is much more densely populated than North America. The United States and Canada are full of wide open spaces. Even as the bird flies, it's well over a hundred miles further from New York City to Chicago than it is from London to Berlin.
The total land area of Europe is less than 4 million square miles. The land area of the United States alone is nearly that large (if you include Alaska). The same is true of Canada alone.
The other factor working against rail travel is that it inverts the normal pattern for transportation. While bus travel and air travel both feature private service providers utilizing public infrastructure (roads, highways, bus stations and airports), rail travel features a public service provider (Amtrak) utilizing private infrastructure (freight rail tracks). As a result, passenger rail travel will always play second fiddle to freight rail travel. Tracks are maintained to legal minimum standards or minimum standards for freight rail traffic. None of this is conducive to high speed rail travel.