I don't know about easier or not, but the skills required have definitely changed.
Yes, it is certainly much easier to actually fly a good course with GPS than it was without it. But with that comes a whole different type of knowledge required.
I did my instrument rating pre-GPS. Every aircraft at the USAF Aero Club, while not identical, had the same basic equipment - VOR, ILS, and some had NDB. They all had standard CDIs, no HSIs. With these, if you can use one type of VOR receiver, you can use pretty much any other common type. Not a lot of difference. Okay, on some you change the frequencies on the unit itself instead of with a separate radio, but that takes about 3 seconds to figure out. "how to turn on the ID feature" was about the toughest part to learn.
Now, however, you have to learn that stuff still, but you also have to learn how to program the GPS unit - and if you're hopping around between different airplanes, you may have a KLN-94 in one, a Garmin 430 in another, maybe an Avidyne in the third. So from this standpoint there's a whole lot more to learn, and the buttonology knowledge for one unit may not transfer to another unit. Add to that some having HSIs, some with G5 or Aspen panels, several different types of autopilots, and each plane can become challenging to understand how everything's integrated. In the past I had no problem learning this stuff, because there WAS none of this stuff in regular rental GA airplanes.
Another example - partial panel. It used to just be "vacuum system fails taking out your AI and DG" - every plane was basically the same as far as effect goes. But now? As a CFI I have to come up with a different "partial panel" for each plane I get in. Is the HSI electric but the AI vacuum? Both electric? If one fails what effect does it have on other systems? Is it an AHRS failure or an ADC failure? Does that cause other systems to no longer be useful? Will the autopilot be usable or not? If the DG part of the HSI fails is the CDI part still usable? System knowledge has become a big issue, whereas before it was pretty straightforward.