You ignoring certain future disasters just because they likely won't happen in our lifetime is like old people building a non-flood proof retirement house in a 100-year floodplain and then leaving it as an inheritance. It would have been wiser for the retired couple to put assets in a non-flood plain house to leave to their children.

This isn't at all like the Gambler's Fallacy because the Gambler's Fallacy's purpose is to highlight that for one person, odds are they will never enjoy success. My point is about all of humanity, and the opposite: That despite the low short-term odds, over the long term it is a certainty that humanity will face these civilization-ending disasters. Sure, the odds don't jump because it doesn't happen any one year, but civilization-ending disasters will eventually happen; are you trying to deny that they will certainly and definitely happen? Your Gambler's Fallacy references would seem to indicate so.