> Because it would cost too much. About 90% of commutes are driving, versus 5% for transit (mostly buses). But even though transit accounts for only about 5% or commutes, it accounts for 25% of spending at the federal, state, and local levels (combined): https://www.pewtrusts.org/en/research-and-analysis/articles/....

That's disingenuous. The driving infrastructure includes both what the state provides as well as what private funding spends (i.e. that cost of the all the cars, fuel etc). The transit infrastructure funding is entirely public in nature.