Assuming that in the future most jobs will be replaced by artificial intelligence or other advanced systems, is it (in your opinion) highly likely that the powerful figures of this world would want to commit genocide against a large part of the world’s population, or would we be dealing with true philanthropists?
Whatever would make life easier/more pleasant for the trillionaires is what will happen.
That said, population is declining in the developed world anyway. People aren’t having kids, governments won’t need to do anything.