awk is irreplaceable on the command line because there's not any other good way to extract columns (awk '{print $2, $3}') or parse/work with numbers. How else would you print a running total for select columns easily? awk '$4>3 { x+=$3; print $2, $3, x}' It's the only tool that's aware of numbers, unlike grep and sed.

My big new power move for awk is -F. You can use any regex as a field separator! Mind blown!