Great replacement implicitly assumes that people who don't have children are part of the conspiracy.

You could now counter and say that these people are following the incentives of the system to not have children so they do not have to be aware of the conspiracy, but how is that exclusive to a specific race? The grandchildren of immigrants will be replaced as well.

I see. There are two parts.

One is a fact, white people are replaced by mostly Muslims and second is a theory 'with the complicity or cooperation of "replacist" elites'

The conspiracy theory part is that it's the Jews, vaguely defined globalists, or some other group they don't like trying to exterminate white people for some unstated reason.

They don't blame groups like business owners openly calling for cheap labor to be brought in.

On German TV this continually alternates between official state policy and debunked conspiracy.