As a counterpoint, I think Japan's investment in rail networks has paid off considerably. I suspect that country would be far worse off today if they didn't have the transportation networks they do (both HSR and normal rail).
Not only does it result in fast, convenient, walk-on travel between cities, it also results in a lot less gridlock meaning less commute time wasted, and more affordable, walkable real estate.
It’s a sample size of 1. Japan is doing great with HSR but also the economy has stagnated for years. Perhaps HSR creates wealth but the lack of flexibility is a long term liabaility?
Not only does it result in fast, convenient, walk-on travel between cities, it also results in a lot less gridlock meaning less commute time wasted, and more affordable, walkable real estate.