Fugaku is not a pc. Its a computer, but not a pc. Its a supercomputer :)

Its a slippery slope, yes, but its one that separates a personal computer from any other device that just happens to compute something.
I get the point though, what makes the arm ampere system a pc and the phone in your hand not? It both has a arm cpu and hardware connections after all :)
Same arguments count towards the playstation or other consoles