As CPUs get faster, operating systems get slower, so really the purpose of these faster chips is to just keep up
This is cute to say, but not true.
It may not be true for OS's, but it is often true for applications.
The contemporaneous versions of Word and Excel on my then-new mid-range 2008 based MBP were snappier than the contemporaneous versions of Word and Excel on my then-new top-of-the-line BTO 2104 MBP. Plus spinning beachballs are much more common with the latter than the former.
So in some ways the chips (at least for applications requiring single-core performance) are not keeping up with the added overhead that accompanies the newer apps.
Here's a comparison I did using the same machine (the 2014 SSD MBP listed in my profile below) with three different versions of Word, along with TextEdit and Pages. This is not disk I/O limited. After the clipboard contents are copied into Word (and I assume Pages as well), the programs have to "process" it for formatting. So nearly all of this is due to application overhead.
Note the stunning difference in overhead between Word 2008 and Word 2011/2016. My 2014 MBP would need to have a single-core speed 10x faster than that of my 2008 MBP, to have Word 2011/2016 on the former be as snappy as Word 2008 on the latter. And since single-core processing speeds didn't increase 10-fold between 2008 and 2014, we're actually going backwards here in real-world user waiting times.
Time to copy contents of 3 MB text file (114K lines) from the clipboard into:
TextEdit (Yosemite): < 1 sec
Pages (Yosemite): 10 sec
Word 2008: 14 sec
Word 2011: 142 sec
Word 2016 (Preview): 121 sec
And don't get me started on Excel. I often need to switch quickly between tabs, and the delay in doing so (as well as the delay in renaming tabs) drives me crazy.
Part of this is that Office was at the time (and I find still is) poorly optimized for the Mac. Here I performed the same test, at the same time, on the same machine, in Bootcamp under Windows 7:
NotePad (text editor, similar to TextEdit): < 1 sec
Word 2016 (Preview): 18 sec (8 x faster than under OS X)
Contributing to the problem is that most of the increased processing power offered by newer chips over the past decade has come from more cores, rather than increased single-core speed. There are reasons for this but, regardless, this means most of the advancement in chip performance doesn't benefit Office programs, which (with the exception of certain functions in Excel) are purely single-threaded (yes, an open Word application will have many threads, but only one of these can be running at a time).