The inevitability of consistency is as consistent as the consistency of inevitability.
Of course it is. Life continues on, whether we want it to or not.
But the outcomes of that life are only as inevitable as the consistency with which we live.
In design, the outcomes of any product are only as inevitable as the consistency with which a designer applies their craft. Deliberate application of empathetic practices will inevitably produce human-centered products that consistently fulfill their purpose.
On the flip side, consistently ignoring human behavior and motivation will inevitably lead to poorly-designed products that hardly ever reach their goals.