Yeah, it's bizarre. Looking at our own species we've barely scratched the surface of what there is to see and explore in regards to our own planet since there's a whole lot of mysteries to uncover such as what exists within the deepest reaches of the world's oceans. Remnants of previous civilisations are also discovered quite frequently as well.
When we eventually explore all there is to find in regards to our own planet, we can safely look at what can be found elsewhere amongst the planets both near and far. It's a safe bet that other species would follow a similar trajectory instead of deciding to just kill themselves because they're bored. Even if some decided to do that, it's not like every single member of the species would opt to do as much. Especially if they weren't a hive mind.
