[eliashaddad]

That is not true at all.

R has inbuilt great parallel tools (check for example the doSnow and future frameworks);

the best packages for data manipulation are mostly written in C (for example data.table and a good part of the tidyverse);

and with frameworks like Drake you can easilly create a Dag out of it that can process complex iterations millions of times. Check the uses of the Rcpp package that makes interfacing C code to R a breeze.

But of course, if you were comparing R to a pure compiled language, you are out of luck.