I think it's just more of the rot. Americans couldn't ever really afford cars to the extent that they were used, no society can. And I don't mean this on a moral ground or whatever, just economically it is a terrible, terrible system to uphold and only ever functioned due to absolutely gargantuan subsidies at every point
But, you know, that works for a while if your average consumer gets a nice treat, but it's simply unsustainable