To me, the central problem is wealth disparity as a proxy for power disparity: our democratic government is more than capable of addressing our ongoing needs and desires if not for the overwhelming, unjust, and unearned influence of the wealthy.
This is why I think Sanders has the correct prescription and Yang is naive: the solution isn't a policy or set of policies to fix specific problems, no matter how farsighted, it's restructuring our political system to be solely answerable to people who it feigns to represent.