IBM sells just the CPUs, is that right? So they are targeting mainframe or other enterprise applications. Whereas Raptor CS that you linked to is selling a desktop version. Other than hobby interest, could the desktop use case be for developers that are building applications for mainframes that use that CPU?
Not to mentioned it takes anywhere between 90s and 5 minutes to boot. It spends over one minute doing init including things like training DDR4 and PCI-e serdes links.
IBM charges 11k for their 8 core POWER9 CPU alone...
Don't fix what's not broken