Well, for one, forgiving student loans wouldn't "reduce the cost of education."
It would increase it. It's just a windfall for universities and loan holders. It did nothing to curtail costs, or address the way student loans are handed out, and their nondischargeable status.
We'd be right back here in 10 years, regardless, because "forgiveness" doesn't do anything to address the underlying problems of student loans, which will continue to be handed out, guaranteed by the gvt, and nondischargeable.