Make that PowerPC, not POWER.
Yes, that's true, but note that the PPC601 was fully instruction set-compatible with POWER. The very first PowerPCs really deserved the name. It went downhill from there. POWER is still around, but PowerPC is still a joke today.
Had Motorola focussed on giving Apple what it needed in terms of low power CPUs, as well as trying to proliferate the portable markets, PPC would have been the hit that ARM today is.
It's not clear that PPC could ever have been as good as ARM. Certainly when Motorola was making PPC-based phones, ARM was faster for the same power... because POWER ain't exactly svelte, and thus PowerPC is not POWER, and zzz. The real punch in the PPC chips was in the coprocessors, and those can be tied to most any ISA.