I'm using a GTX 970 and have experienced no more than a half dozen crashes to desktop in hundreds of hours of play, only two of which have occurred since I disabled the Ubisoft Connect overlay and used the disable "Use anti-cheat compatibility hook" trick.
If anything, I'd imagine that older graphics cards would be more reliable simply because their drivers have had much more testing over time and are generally better understood.
But also remember, two people with the same video card do not necesarily have at all the same system. Amongst any group of users with the same card there are likely to be a dozen different driver versions, a half dozen different versions of the DX11 and DX12 code, different versions and patch levels of Windows, and so on. Fifty different configurations in a hundred different users would not be at all unexpected.
And also keep in mind that the results of possibly inoccuous-looking mis-usages of libraries (including drivers) and the like may be dramatic. Consider the following C code:
Code:
int *p = NULL; /* pointer to an integer */
int i = *p; /* deference the pointer */
While a Java or C# programmer might think, "oh, this should throw an exception," this provokes what the C standard calls "undefined behaviour." If that code erases your hard drive or launches missiles and starts a global thermonuclear war, that's perfectly within spec (from a standards point of view) because when a programmer does the above, the system executing the code is allowed to do anything. Testing, however, cannot find all such situations because it's also perfectly acceptable to go on executing everything else normally, maybe just assigning 0 to i.
Obviously nobody's going to write code that does the above directly, but it's very easy for situations in which undefined behaviour may occur to creep into code. We have good tools to help with this, and most developers (especially triple-A game developers) use them extensively, but it's quite normal for a driver to continue working fine for years with a call that's technically undefined behaviour and then with a new release start exploding in the same case because someone optimized it to get a couple of extra frames per second on some game.