And what exactly does "hitting the end of the runway" entail? Alarmist calls about the economy suddenly running out of resources and an ensuing global collapse

And what exactly does "hitting the end of the runway" entail? Alarmist calls about the economy suddenly running out of resources and an ensuing global collapse have been around for decades. Centuries, really. Remember when we thought that we'd all be fighting over oil by 1995[1]? That sovereign debt is going to collapse? The US at least, has debt figures as a percentage of GDP that are a fraction of plenty of other countries mostly regarded as stable. I'm going to need more info before I believe someone telling me the end is neigh. 1. https://en.wikipedia.org/wiki/Peak_oil https://en.wikipedia.org/wiki/Peak_oil