I think the Vision Pro will be more like the Newton vs current iPads. Something will eventually replace it, but it will be significantly different, not slightly different, like Lisa vs Mac (I know they cut corners for the Mac, changing some nice OS features)
Without the NeXt Cube, we wouldn’t have the modern MacOS, or, for that matter, the iPhone (or Vision). Apple would certainly not be a multi-trillion-dollar company, and the Cube was a commercial flop.
In that case, it wasn’t the hardware, but the operating system and app development framework that made the difference.