Spain had/has the advantage of being a single national polity vs ~8 sub-states that comprise less than a fifth of the national whole. National planning and coordination vs co-equals hashing it out. To echo others, it's not that it *can't* be done, it's that it's going to be *hard*
If only we had a massive national federal structure eh? The GDP of Spain isn’t significantly smaller than Illinois either. We don’t do it because we don’t want to.
That factors into (political) will, yeah. We *could* do such projects nationally, sure, but we collectively decided that infrastructure is one of those things we talk about but never get around to doing until it's almost too late.
I used to work in Public Transportation at a municipal level. The overarching view of PT from the public was "mass transit is for poor people and people we don't want driving." So... college students, poor folks, and (begrudgingly in some areas) minorities of all economic strata.