I'm not sure that's an apt comparison. If you were saying that 32-bit PPC is dead, then the answer is probably yes at least in general computing, though there are still lots of 32-bit PowerPC parts in embedded systems. However, 64-bit PowerPC systems have substantially more in common with "big" POWER. The G5, which was clearly positioned as a member of the PowerPC family (PPC970) but descended from the POWER4, would be the classic example.
Also, the separation kernels that met NSA's highest standards of security initially targeted that for cross-selling into aerospace market. They buy a good chunk of PPC for some reason. Example that was among first certified with data on what was expected: