Have you actually benchmarked it? If your current PCs boosting up to 5.5Ghz that means you have a pretty modern PC and quite a lot more powerful than a Pi 5. Also, you're completely missing out the IPC differences even given same clock speed.

If you're going after perf per watt, then sure the Pi will likely win. But not possible for raw performance if what you said is true about having a modern CPU with 5.5 Ghaz boost clock.