Post modernism died 35 years ago at least. It’s height was with Borges. “Garden of Forking Paths” — all related to the new discoveries (at the time) of theoretical physics, the mixing of fact and fiction, etc.
But the thing is: we’ve all been raised in postmodern culture. Long long time now. 70+ years easily. Birthed into it. Breathed it. 1950s television. 1960s televised revolts. 1970s gas prices, etc. 1980s global theater and 90s push-button wars. All postmodern era.
I say it died because it’s all of us now and has been.