All of these systems work by JIT translation of source-code into bytecode or into an internal data-structure that is then processed using an optimized interpreter loop.   Even “traditional” C++ compilers use that technique, and of course, Microsoft’s dot-Net framework is entirely based on it.   The overhead of a runtime interpreter loop is frankly negligible.   JIT compiling is also an affordable one-time overhead expense.

Well Perl does do JIT translation already, see eval.