It's absolutely not the same thing : the Racket example is not a Brainfuck interpreter, it's an actual DSL inside Racket, which benefits from it's whole infrast

It's absolutely not the same thing : the Racket example is not a Brainfuck interpreter, it's an actual DSL inside Racket, which benefits from it's whole infrastructure (JIT compilation etc.). It's not the Racket language running a BF interpreter. It's the BF language running.