PowerPC traded a lot of blows with Intel in the mid 1990s. But often PowerPC won only in highly specific, highly tuned benchmarks. PowerPC wasn't much behind though either on more general benchmarks. The problem more was that PowerPC was too small of a market so the costs to keep improving it were adding more and more to the costs of each chip. By the time Apple switched, PowerPC was a power consuming beast, couldn't hit 3 GHz, had a half-assed approach to multiple cores, and cost far more per chip. That wasn't where Apple saw the market going. Apple wanted lower power laptops and to stop subsidizing PowerPC that just was getting too old for its own good.