They automatically set up logging, to ~/.hcm/<year>/<month>/<day>/* - on the initiating host,
not on the host you're logging into. This way your logs tend to be easy to find, not being scattered around the
various hosts you're using.
They automatically set up your shell prompts to give good timestamps.
They always set up $PS1 with a CWD, hostname and timestamp of the time the last command ended.
Command start time
They attempt to set up $PS0 with the timestamp of the time the last
command started.
$PS0 is only available in bash 4.4 and up, so if $PS0 is unavailable, these fancy shells
will set up almost the same thing using "trap DEBUG".
They set commandline editing mode to vi, and set $EDITOR to vim.
And so on....
And they set up simple wrappers for su and sudo to preserve these settings.
And they do this without scribbling on your bash startup files!