I use:

    iwashere() {
      sleep $(shuf -i 1-9 | head -1)
      date
      echo "===> $(hostname) <===" > ~/I_WAS_HERE
    }
    env_parallel -Sserver-0{1..5} --tag --nonall iwashere

I like that I can try out the function locally before running it remotely.

I like that I do not have to give xargs a multiline argument.

I am terrible at quoting inside quoting inside quoting, so I like that I can simply avoid the quoting. I also think my colleagues will find it easier to read (thus maintain).