There are no modern examples in the USA precisely because there is no political will to fund them. That political will is undermined because private companies are large and strong enough that they can influence politicians and prevent projects they they would have to compete with.

Your argument has the implication the wrong way around.

Meanwhile, look at China. The vast majority of China's cometlike economic success can be directly attributed to state funding, and many of its successful projects are directly state-run. That's because China still plays industrial politics that are concerned with economic growth and public welfare instead of rent-seeking.

The current system rather heavily optimizes the ability to make resources into more resources for the shareholders. See e.g. Uber.

The current system selected people that have maximized shareholder value and financially engineered it into other financial assets that provide power under the capitalist system. This includes private equity services that have simply squeezed money out of consumers for no increase in quality of life, or companies that managed to avoid the consequences of the externalities of their economic activity.

> And what is stopping countries from doing this today? This isn't an either or thing, public projects can still exist, there is no law of nature saying that massive companies are the sole source of innovations but for some reason people treat it like they are mutually exclusive. You bring up projects from decades ago but are there any modern examples?

Regulatory capture and lobbying that attempts to force a profit motive behind every large government initiative when the profit motive substracts value away from society at large.