The funny thing, is that it actually never makes sense to "predict humanities demise", as noone will be able to witness your prediction coming true. You won't be able to reap any benefits of your true prediction, so you might as well bet on survival
Eh? Predictions aren't always about reaping benefits. Not every prediction comes with a bet that you can win. Sometimes it's just what you think is the most likely outcome, whether you have a stake in the outcome or not.
There's a 100% chance that humanity will die, eventually. We surely can't survive until the end of time. Even if we could, you wouldn't be able to witness that either.