[MayeulC]

Yeah, it is very useful and allows environment variables, so you can do

   /usr/bin/env -S myvar=${somevar} ${someprefix}/bin/myprogram

However, as another commenter wrote, support is not universal (looks present in RH8 but not RH7 for instance). Also, the max length of a shebang is usually limited to about 127 characters.

So sometimes you have to resort to other tricks, such as polyglot scripts:

   /usr/bin/sh
   """exec" python --whatever "$@"
   Well this is still a Python docstring
   """
   print("hello")

Or classically in Tcl:

   #! /usr/bin/sh
   # Tcl can use \ to continue comments, but not sh \
   exec tclsh "$@" # still a comment in Tcl
   puts "hello"

Such things are not usually needed, until they are, and they make for fun head-scratching moment. I would personally recommend against them if they can be avoided, as they are relatively fragile.

I'll leave the self-compiling C language script "shebang" as an exercise to the reader ;)