Jared Diamond was good with Collapse but much better with: The rise and the fall of the third Chimpanzee.
Collapse is (for my feeling) too limited to small size civilisations. So the real collapse that happened to many civilisations did occur too, but very likely in a totally different manner.
What happened to:
A.: most civilisations: war and economic crisis because too high military spending,
B.: some civilisations: new illnesses unknown at that site, coming from the "outside",
C.: one or two only: big volcanic eruptions,
D.: many civilisations but not clear if fatal or survivable: violent and rapid climate changes.
E. some civilisations: exhausted by nonproductive priests or state-representatives and collapsing at first major problem,
F.: only one or ?, fragmenting into nonexistence after a long period of decline (West Roman Empire).
Maybe none of the problems above will cause our civilisation to collapse. Globalisation makes everything different. But local collapse may occur in many regions - as usual today.
Open question: will mankind be ready to live with changing energy supply and organise its distribution and conversion into needed other forms. And in future consequence quit the burning of fossil fuels: oil, gas, coal too expensive then. Bio too expensive today, causing starving others is not a recommended way.
Open question: will there be any natural habitat in 30, 100, 500 years? Will human population stabilise or not? Will steadily growing population trigger catastrophic failure as in experiments with mouse families with unlimited food supply?
I agree that Jared Diamond (any of his books, look also to Mrs.Diamond's book!) is very good reading!