Mass extinction is a common argument for the atheistic implications of evolution. Mind you, one can have mass extinction apart from evolution. Those are separable.
But the basic argument is that it's pointless for God to create species which he subsequently destroys. They just come and go. And not just species. Entire ecosystems come and go in the course of natural history. The unique fauna and flora of that particular epoch arise, exist for millions of years, then pass out of existence, to be replaced by the next set of temporary fauna and flora.
For the sake of argument, let's grant conventional geological timescales. Christian theology concerns the future as well as the past. Eschatology as well as protology.
Suppose, in the world to come, God makes time-travel possible. We can go back in time to observe the past. Perhaps we can't interact with the past. Rather, we're like immersive spectators. Something we can experience, but not something we can change.
There are, in fact, many men who'd love to go back in time to observe dinosaurs, or extinct Ice Age animals, or see the exotic flora and the wild ancient landscape. And maybe God will make that possible for the saints.
If so, then it's not "wasted." Rather, it's like a historical holonovel. Something that God wrote for our enjoyment.
Now, an atheist might object that this is one of the things he especially dislikes about Christian theology: we can always postulate a supernatural solution. That's just too convenient.
But, as a matter of fact, if Christianity is true, then it really does have wide-open possibilities which are foreclosed by secularism. That's not ad hoc. That's integral to the nature of the belief-system.