My assumption (and I could be wrong) is that whenever you do something that's ultimately CPU intense, perl dives into C code. The sort of stuff you do with perl tends to be a lot of string manipulation and it turns out perl is pretty hyper optimized for that sort of workload.

Other languages could do the same, but often they have a few more layers before they start running that C code.

I'd be curious to know if the perl grammar also somehow lends itself to being fairly optimizable for it's interpreter.