I think the default mode is lack of population and getting outcompeted by pro-natal civilisations, like amish etc. You need to provide a reputable source for why is that not the case.
I must be either misreading your point or not recognizing intentional irony. I would expect the Amish to average a lot of kids per family, but I'm not aware of any instance of a civilization disappearing due to being outcompeted by them.
The population maths works out exponentially it will likely take a 150 yrs to reach 300M~, the only moat liberal culture has is mimetic and we have seen that being trampled in realtime with post-truth era I am not optimistic about that.
I don't need to provide anything, I'm not the one making claims. (Especially ones as wild as this.)
That's... That's not how discourse works.
Well I need to be shown why the default darwinian assumption which has held for millions of years won't eventually win again rather than your historical aberration.