

Individual low odds things don’t happen frequently, but collectively they happen a lot more often because there are so many low odds things with potential to happen.
Yes. This is why you shouldn’t play the lottery even though you may see people win it fairly frequently. Most people lose, and the cost of anyone winning is higher than the payout. Similarly, the cost for preparing for some incredibly low odds events is higher than the likelihood it’ll ever be useful.
Yeah, an asteroid detection and diversion system makes sense for a society. Those odds aren’t that low and the cost isn’t that high (and the other benefits it provides may may it regain its cost in value). It doesn’t make sense to prepare for a black hole hitting Earth and wiping us out though, for example. The cost would be insane and the likelihood is effectively zero.
However, you as an individual shouldn’t waste your time making an asteroid detection and diversion system. The cost is way more than you can afford and the likelihood is very low compared to events that could happen at any moment. It’s a waste of your resources and time to consider. Preppers are working as individuals usually.