Decades overlap -- the 70s are very present into the mid-80s; the 80s; into the 90s, even beyond.

For the Digital Age (that's ultimately what did it) it took a little longer, because it was its ubiquity that caused things to go to shit. Eventuations like handing kinetic work and creativity over to machines; infusing the Third World into the discourse; delegating very human thought to LLM's etc., were contingent upon the digital means to do so and the implementation of the means--taking some time. Thus, it wasn't 'til about the 2010s we realised that owari da was upon us.