Sustainability is a behavior only learned when absolutely necessary, when the constraints of material existence impose themselves on the living. Growth will always happen outside of these constraints.
That is to say, some behaviors will reduce growth now in exchange for stability (i.e. more growth later, or less growth loss later), but those are hard-won and they are not the default. The default is always growth up to capacity, and we don't actually know what that capacity is.
Malthusians have been dooming for centuries. We can accept that at some future point, they might be right, but it is always wrong to assume they are inevitably correct at the present moment. Growth can and will be pursued until it is no longer an option. It's not weird, it's not a fixation, it's not a hypnosis. It's just life.