Older versions of PDF files and readers don't know or care about what happened later. PDFs also did shady shit like being able to embed JavaScript actions and other files. They also became Turing complete when they adopted Type 4 functions in PDF 1.3 that still aren't deprecated in 2.0.
LaTeX subsumed most of the human authoring uses of PS where it was used in academia.
Older versions of PDF files and readers don't know or care about what happened later. PDFs also did shady shit like being able to embed JavaScript actions and other files. They also became Turing complete when they adopted Type 4 functions in PDF 1.3 that still aren't deprecated in 2.0.
LaTeX subsumed most of the human authoring uses of PS where it was used in academia.