Millions of species even went extinct before modern man was ever here.
Just because it has happened, doesn’t mean we should endorse and accelerate it. What we do determines the future.
Why?
However, in my opinion, it's a rather uninteresting hypothetical because human activity absolutely does play a huge role in the extinction of species today.
What about the ramifications of doing so?
I’m not sure fiddling with natural levels of extinction are smart.