Just after WW2, there was the idea that improving the education of the people in general would pay back dividends many times over in economic growth and tax revenue, so there was the expansion of state universities that were low cost to the student as well as programs like the GI Bill. So college education shifted from being largely for those from wealthy families to being accessible to a much larger share of the population in terms of parental SES (although there were still educational access and opportunity limitations based on racial segregation that would take considerable action to remove).
Actually, it seems to be a common opinion around these forums that cost should be a flat fee for all without financial aid discounting, which would make college inaccessible to those from lower income parents, but probably cheaper for those from “upper middle class” and wealthier parents, returning to the pre-WW2 state of college being largely for those from wealthy families. Even some states’ public universities (e.g. in Pennsylvania) are moving toward this model, with list prices discounted relative to private universities’ list prices, but not much financial aid, rendering them unaffordable to many with lower income parents. But that may result in lower future economic growth and tax revenue, as many with lower income parents are unable to develop their talents through college education.