Things like word used to be much better in speed of the interface - it used to take fewer clicks to do stuff
Go open that Excel 97 with a spreadsheet containing 65,537 rows.... Oh, you can't.
People aren't building modern software that does the same set of things so attempting to measure it is much more difficult than opening up a zillon year old VM.
Most people don't care if their spreadsheet takes 1 second or 10 seconds to open. What they do care about is "Bob sent me a spreadsheet and I can't open it" or "The app crashed and lost all my data" (and technically I've seen spreadsheets crash plenty, but they tend to have a recent copy of the data saved which is eating up resources to monitor and do this). And things like "I want to hit undo 50 bajillion times".
And that is just feature bloat. There is a ton more 'just import a library' for that bloat because adding libraries is generally much easier when it comes to fixes then finding the place in your source code and fixing it.
Install Windows 2000 and Office 97 in a VM. Word will be blazingly fast compared to the latest version. What features do you ever use in the latest version of Word that weren't present back then?