Is there a standard anti-pattern or something that could be referenced, to argue that when a system reaches a given complexity it will become unmaintainable and will collapse?
Something like systems are never finished they are just abandoned, just a more serious version.
Here is a suggestion: the Lava Flow description. It isn't exactly what you're talking about, but it might, with a longer description of the project.
I've personally encountered this monster on several big scale projects.