There is one point it doesn't explain, though. It appears that the severity of the debt cycles can be reduced and social stability improved if the economy weren't fueled by credit to such a degree ($3 trillion in money, $50 trillion in credit, wow). So why have so much lending? The video does briefly answer that question with the need to finance economic investments (i.e. things that can improve future income, e.g. a tractor).
That is only a partial answer. The narrower version of the question remains: why do we need so much lending for consumption? Is there any benefit at all in financing consumption with debt? It does increase present spending and economic activity, but only at the expense of reducing future spending and hurting future economic activity.