Indeed, but a lot of railroad startups went out of business because their capital investments far exceeded the revenue growth and they went bankrupt. I'd bet the same for AM radio companies in the 1920s. When new technologies create attractive business opportunities, there frequently is an initial overinvestment. The billions pouring into AI far exceeds what went into .COM, and much of it will return pennies. The investors who win are the ones who can pick the B&Os, RCAs and GOOGs out of the flock before everyone else.[0]

[0] "Planning and construction of railroads in the United States progressed rapidly and haphazardly, without direction or supervision from the states that granted charters to construct them. Before 1840 most surveys were made for short passenger lines which proved to be financially unprofitable. Because steam-powered railroads had stiff competition from canal companies, many partially completed lines were abandoned."

-- https://www.loc.gov/collections/railroad-maps-1828-to-1900/a...