Please offer a parallel MacOS release for each image that has preinstall bash (5.x), coreutils, and GNU utils. Bonus points for aliasing date to gdate, sed to gsed, etc. The default versions are relics, and Apple can't update them due to licensing issues.
brew install bash, coreutils, gdate, gawk, gsed, findutils shopt -s expand_aliases
alias date='gdate'
alias awk='gawk'
alias sed='gsed'
alias find='gfind'
The aliases will have to get thrown into an RC somewhere. Maybe $BASH_ENV.