Sprinkle on top a nascent anti-natalism coming from the environmentalist left and you have a recipe for a societal disaster.
The sexual act has been 'decoupled' from the procreative act since forever. People have always had ways to avoid pregnancy (some more successful than others) and sexual acts have always entailed much more than procreation. Not just within our species; look at how bonobos use sex for purposes other than procreation.
And falling birth rates in developed countries are not because of this mythical 'decoupling' you write about. There are many reasons for people not having as many children today and those reasons have been trending for a long time before the invention of the modern birth-control pill.
> The decoupling of the sexual act from the procreative act was transformative to society and I think we're just becoming aware of the consequences. Every developed nation has to import mass quantities of immigrants just to mask the problem, causing social unrest in their traditional populations
What is the problem you're referring about? Most would argue the world is over populated. Cost of homes are rising from scarcity to how many people there are. Most young people cannot afford a home to even consider having a child.