With some notable exceptions applications have become slower in a way that is just fundamentally unnecessary. Fifteen years ago you could do text editing, browsing the internet, chatting and possibly editing spreadsheets all in parallel on a machine that today would not be able to do anything with the same (but upgraded!) applications. This is not due to features that are "just more expensive" (though as said there are some notable exceptions, like probably decoding 4k video on youtube) but because the development process has migrated further and further away from any sort of performance concern as the platforms you could expect became faster.

That is not to say the computing landscape was fundamentally better fifteen years ago. I think it is almost the same. What has really improved is the general usability and stability of drivers (no more rebooting, random freezes and if you run linux your X server not working every other update), which is definitely something to be proud of. What has not improved is basically everything else and I'm really not sure why.

If I had to guess I would say it has something to do with managers the world over just not giving a shit about delivering something good, as long as it sells. As platforms have started having more headroom for bad software, "as long as it sells" has started to have a wider and wider performance profile. Landing us where we are today: with many of the same features, much less privacy and every other app packed with an entire browser "because it makes it easier to develop".

Even as recently as last year I had a more relaxed stance about this but I guess it has just been bothering me now that I have more time to think about the state of my work (and everyone else's).

Edit: I see now I responded to something slightly different than what was requested.

Modern (AAA) videogames should not be bought or played because they are produced by a sick and exploitative industry that really needs to die. Instead, we can prefer the indie games that work well with what they have: Generally a lower graphical budget that runs significantly better on hardware that is "out of date".

For office-type processing and messaging, there are generally application choices and tradeoffs that can be made for more performance instead of more eye candy. The average office worker (which I guess includes most people here) will not materially care that it doesn't look quite as good. Another upside is that as a company you don't need such an enormous budget for office hardware.