I was rolled out with an "Enhanced" desktop a few years back. It wasn't really all that enhanced than the normal desktop that all office types got. I (and a subgroup of others), do a lot more technical work, and use specialized software. However the folks in charge of the specs (and bean counters probably) didn't either know that the enhance spec was barely better then the base, or figured it was good enough. A bunch of us rebelled, and worked with the vendor to create a new more appropriate spec.
That said. Much of the work that used to be highly impacted by graphics cards, such as GIS, CAD, and a host of others, aren't so much anymore. It is mostly CPU dependent now. Most modern CPU of middling power are sufficient for most tasks. From my own experience the two biggest improvements are multiple monitor (also used to be video card dependent, now pretty much anything can), and RAM for large tasks which is dirt cheap anyway. The monitor allows someone that say needs to see tables on one screen, and graphics on another, or application on one, and DB on other much easier to get things done. I recall trying to use 4 really small windows on a tiny screen rather than flipping through them all the time. RAM simply allows someone who is processing a lot of data to use maybe one process rather than have to create 5 processes out of fear of running out of memory and having to repeat it all.
So while the base is good for most, there are a semi-large subset that do need something a bit better. However that bit that needs to be better has evolved over the years, and is frankly not as different as it used to be (at least in things I am exposed to). The few changes that make the most impact, are so cheap that not to do them borders on insane, as you won't pay the difference of say a 75$ annual lease payment for an employee you pay 70,000$ to simply make them happier as their job might be a little less irritating? You can still technically do stuff on a base spec, it just takes longer, might be more work, and be more frustrating. Though sometimes it does have its perks.... When I first started as an entry level, they gave me a a base box (IBM PL300 or something if my memory serves)... There was a time where I was pretty much just doing large data processing of GIS data. I would put it into smaller more manageable chunks, and automate them together in a batch. Occasionally I would miscalculate and run out of memory and have a fail, and would have to redo a few but it worked pretty well more less. However, while it was processing the computer was using everything it had, and wouldn't respond to anything else... I got into the habit of bringing a book to work. There were many days where I would do nothing but processing, and I would have the feet on the desk reading a book for the entire day(s). I had my manager come in and question me, where I would point to the spinney hourglass (or whatever it was) and say "processing". So in that way it made me happy. Though from a business standpoint, they were not really utilizing me nearly as much as they could. Of course as entry level they weren't exactly paying me all that much anyway so they probably didn't care all that much anyway. :)