Dumb terminals were extremely prevelant throughout the 80s and into the early-mid 90s. Most people just didn’t know that they were “dumb terminals” and either just thought they were early desktop computers or just heard them referred to as a “terminal”. That same library didn’t update their dumb terminals to actual computers until the mid 90s, but they did however remove the light pen in favor of a keyboard at some point well before then.

This is Lenny. Most users probably do. Good percentage still have a few. A few of us make new ones now and then.

(Technically not dumb ones, though. And completely excluding terminal emulators, which are of course ubiquitous.)