When the next collapse of civilization happens those that caused it will be holding most of the money. They will then use this money to rebuild civilization and make yet more profit...
a) they have a lot of influence over how humanity reacts to existential threats
b) they're nowhere near as concerned about the collapse of civilisation as everyone else.
Future conquests (Inca, etc) were aided by the devastation of disease that wiped out stove populations.
Our situation isn’t so different. Look at how quickly the Soviet state degraded into near anarchy and what happened when the pieces stabilized.
How do you define “suffer”?
They lost their previous lifestyle and creature comforts. Their public infrastructure fell into disrepair and the ability to build its like was lost. Trade networks were disrupted and many products and materials became unavailable. They lost much of their power and wealth (lands, houses, possessions, businesses, ...). Many were killed. In Rome proper foreign invaders came and demanded tribute, sacked their city, tortured them for information about where their wealth was hidden, stripped all of their public buildings of valuables, and so on.
The difference today is that intellectual property is more highly valued. When law and order breaks down, software, for example, has zero marginal value.