I was watching Halt and Catch Fire and in the first season the engineering team makes a great effort to meet something called the "Doherty Threshold" to keep the responsiveness of the machine so the user doesn't get frustrated and lose interest. I guess that is lost to time!
Office suites have never been good, but office suites in like 2005 seemed to stretch systems to the breaking point.
Lots of consumer software has always sucked out of the box, I guess if you are here you were possibly a technically savvy kid at some point, is it possible that you were just more selective about the types of programs you ran when you were using the computer for fun?
I still have this instinctual reluctance to change screen resolution in a game's setting screen, even though 99% of the time it's an instantaneous thing these days.
I have fond memories of that, but basically the editor was a UI into a linked list with a blue screen. So not comparable to what people are being asked to do with Word and 365 today.
My personal beef with Word is that it struggles so much with long documents. Trying to read, say, a 300 page spec from 3GPP is miserable.
If you get bad performance in a game nowadays it's a good idea to try proper fullscreen. Alt tabbing might be slow, but the game will run better.
This is not an inherent limitation of CPUs but a part of Windows' exclusive fullscreen concept. Just another thing that was simply accepted as the way things are instead of being improved (until exclusive fullscreen went out of style).