Why would this limit social and economic mobility?
If it does limit social and economic mobility, does that mean our process for mobility is flawed? Does there need to be a reassessment of what is valuable in society? Are plumbers or mechanics "less valuable" than a business analyst or marketing professional? What about a hospice care worker or a grocer? Are we focusing on college degrees because of historical baggage? Should we have more courses in computer science or agriculture, or more courses in literature? More of all? Less of all?
Recall that social and economic mobility don't just go up, they go down too.
Can we look to countries like Germany that have healthy vocational and technical training programs?
And why would you think that I would want to severely limit social and economic mobility? What are you implying here? I don't get it.
One major problem today is that most bachelor's degrees are required but not sufficient for many not-particularly-socially-upward jobs. So go in debt to still not have mobility.
If you do that, you severely limit social/economical mobility. Is that what you want?