Most of them just use whatever is convenient - BSD's, MacOs, Linux and whatever turns them on.
My main interest in the history is mostly pre-divestiture of ATT. The history of pipes everyone knows, but some don't realize the convenience of "everything is a file" - like device files you could merely cat to, without having to drop into a Job Control Language subsystem, answer about 20 questions about the file specifics, and print or save.
cat myfile > /dev/lpr
Mindblowingly convenient. Suddenly you don't have to be the device-driver with a lot of arcane printer device knowledge as you would with other systems of the day.
My biggest history kick is how McIlroy showed back in '86 or so that most everyone is still using 1960's JCL techniques, when using DD with IF= and OF= pairs.
Nowadays, I just do it the unix-way:
dd < input > output
I make far FEWER dd mistakes using the unix notation - it just reads right to me, whereas with IF / OF pairs, I easily get them mixed if I'm not paying attention.
That blew my mind because even today, everyone uses the JCL way of doing it from the 60's. I thought that was the only way until a few years ago, and just smiled how this could be hidden unless you dug up the history...
I'm weird I guess - all this stuff we take for granted. Imagine running unix without any pipes and having to use redirection and temporary files to delete all the time? Or no device drivers - dropping into a subset language of it's own just to manipulate files getting them into and out of filesystems based solely on a manufacturer's spec-sheet - all of them different and YOU have to get it right...
Dunno' all these years and it still seems so innovative to me...