I often meditate on this - can even the concept of index fund retirement survive an actual depopulation scenario?
Of course, older forms of retirement can still work (have ten kids each of who have ten kids and you command an army in retirement; perhaps they’ll even call you King) - but aside from that where does the growth come from when not from population or immigration?
Index funds will survive anything short of a complete collapse of the financial system. Even if returns are low, they only have to be better than the alternatives (on a risk adjusted basis).
Sure - but being better than the stock-alternatives in a fifty year bear market is cold comfort; and many retirement plans are built on assumed real returns that may never be seen again.
if the consumer base collapse what will keep the stock fundamentals going ?
Stock values may decline but there will still be index funds holding those stocks.