Kids today don’t realize how much “printing” to files your computer does.

This is as much linguistic tomfoolery for humans as it is a con for computers.

I dont know the history, but the most likely case is some microsoft engineer implemented the "print as pdf" option to get around an adobe restriction in the far past, and now we have this weird convention where you can "print" to only 1 filetype to "save" it.

Beyond that, also, what's so hard about clicking on "File > Export As... > PDF" which is literally in the file menu on LibreOffice at the very least. I don't know about MS Office, but I would assume it's the same.

Postscript (not the P in PDF, even though I think it should have been) is how Portable Document Format is made.

PostScript’s original purpose was for formatting documents to print with laser printers, but to also interpret font hinting and display features for lower resolution printing. But it required printers to process them before rasterization.

It was so good at this that it made sense to also use it for the much lower resolution of computer screens once computers were powerful enough to do the rasterization themselves. Hence the PDF replacing most .PS (PostScript) files, unless you were a graphic design student in the late 90s.

When you are saving it as a .txt file, you are printing it as a .txt file, the computer sees no difference.