I'd expect every new generation of computers to not last as long as the last one, we keep reducing the transistor size and that means more fragility. I'm half surprised modern GPUs make it through shipping without melting from static.
My guess is that the most long lived computer gen could be one that still uses through hole components. Not a very useful machine by any metric though I bet.
On the flip side, a lot of those old through-hole memory chips have failed. I'm not sure what the mechanism of action is, but it likely leads back to some kind of (at the time unknown) manufacturing defect. Every new generation requires higher purity and better quality control (because those tiny transistors are less tolerant of defects). If we optimized for longevity rather than flops per dollar or per watt, we would likely keep making the same hardware for a very long time, optimizing the process along the way and learning about the pitfalls. Maybe you can see such things in the military or industrial computing spaces.