Those dynamic languages are only performant when you add a bunch of type information. You wind up writing a simulacrum of C and it still under-performs.

The idea is that there is some useful speed for much of the application by using native compilers. Higher speed might be needed only in parts of the program. Then a type inferencer, etc. comes to use. If that's still not enough one calls C or assembler routines - but, say, 95% of the application can be written in Lisp.