My first printer was an HP LJ II+ with the PostScript cartridge. I had to buy extra RAM for it and for a while, I had more RAM in my printer than in my computer. A few years later, I bought a fancier PS printer that printed ledger size pages and handled duplex and again I had more RAM in my printer than in my computer. I used to occasionally write PS documents by hand (one was to print out country placards for the Model United Nations club at my college where for country names which were especially long, the text would be auto condensed.
These days, with the advent of printing subsystems in the GUI and the fact that software no longer needs to handle the printer directly, I don’t know if anyone ever buys PS printers at all anymore.
PDF, although it can resemble PostScript, is not PostScript. PostScript is a Forth-derived Turing-complete programming language that, in an era of generic printer drivers, offers little benefit anymore since it’s unlikely that an OS printer interface would take advantage of its capabilities. In the old days of programs managing printer output directly, it was handy to be able to do things like decompress TeX PK font bitmaps on the printer (or even more dramatically to send binary data for illustrations to be decoded and decompressed on the printer), but the set of printer primitives that are supported by OS printer APIs is constrained enough that nobody will do these sorts of things anymore. PDF is now essentially the lingua Franca of print interfaces and the programmability of PostScript is more a liability than a benefit.
These days, with the advent of printing subsystems in the GUI and the fact that software no longer needs to handle the printer directly, I don’t know if anyone ever buys PS printers at all anymore.