I think multicore CPUs did a lot to kill the momentum of OpenMOSIX. I remember playing around with clusterKNOPPIX back in the day and being quite impressed by it, but it seems that multiple cores and threads per core became the norm and the cores themselves got a lot faster.

On the other hand, combining multiple 64-core Threadrippers into a single-system-image cluster has a certain appeal to it.