I'm very far from an expert in this field, sorry. PCM (and other resistive memories) are definitely still a thing, though - they've been used for in-memory comp

I'm very far from an expert in this field, sorry. PCM (and other resistive memories) are definitely still a thing, though - they've been used for in-memory computation, doing vector-matrix multiplications directly in the memory cells and thus saving massive amounts of die area over using separate CMOS logic, so they're probably going to replace on-die SRAM for some applications.