That is a very nice example you have there. The Plus is my absolute favorite simply because it was the first machine that my family ever had. Your interpretation of the 90s events are somewhat correct in my mind. Each generation of computer blew away the next. However, what was acceptable to use also varied greatly. For instance, until the internet really became a big thing, I'd say the late 90s, people would use a Plus from the late 80s right beside a II or Quadra series Mac. The reason is the same that you can use a now ten-year old iMac next to a new one: the key, core functions are the same. Computers were used for their more pedestrian functions that we now take for granted: word processing, spreadsheets, page layouts. Throughout the 90s, it was perfectly acceptable to, say, have a printed sheet that was made on a Plus in black and white. That is akin to today a machine being able to connect to and reasonably search the internet: as long as it can do that, no one really bats an eye at how old it is. Now, the guy trying to do 3D modeling and the like back then would scoff at a Quadra and only want the newest Power Mac...just the same as someone who needs a Mac Pro today would not use a Mac Mini for their work. But, the vast majority of people used the Plus, Classic, etc, for years upon years. Another reason for that was cost: computers were a lot more expensive comparatively than they are now.
Just my view having grown up through that time. I find it very satisfying to have started as a kid with a Mac Plus, and by the time I was 18, the G4s were out, the iMac was big, and so much had changed in such a little time. A "magical" experience if I say so.