These things go in cycles, economies are dynamic, they do not just rely on a single area of growth, they react to consumer demand, new and emerging markets, restructuring and so on.....that is not to say that consistant growth is always sustainable, as we have seen it is not, but it also doesn't mean that the world is suddenly going to go bust either.
As for the current standard of living, well that is entirely subjective and differs from nation to nation and region to region.
Debt is not necessarily a bad thing, it is unstructured, unmanaged debt that is bad and at the end of the day, if it came to pass that global economies were collapsing then that debt would either be written off and defaulted on a'la China, Iceland etc or restructured in some way.........sometimes debt is simply devalued to such an extent to be virtually worthless and ultimately nobody wins if global economies collapse.