Sort directory list in reverse order

Let ls do the sorting:

ls -l -r /usr/bin

or just

ls -lr /usr/bin

The standard -r option to ls make it sort the list in the reverse order to what it would otherwise do. If you ask ls to sort on the modification timestamp with -t, -r will reverse the order of that list too, etc.

Your command pipeline sorts on the permissions, ownership, etc. that ls -l outputs, and would not consider the filenames unless all other information for two entries were identical.

You did not ask about this, but since it's a common thing to want to do and often the next step after asking about ls output ordering... To actually extract the filenames sorting first or last from a directory listing, don't use ls, instead use an array or the positional parameters:

The first filename:

names=(/usr/bin/*)
printf '%s\n' "${names[0]}"

or

set -- /usr/bin/*
printf '%s\n' "$1"

The last filename:

names=(/usr/bin/*)
printf '%s\n' "${names[-1]}"

or

set -- /usr/bin/*
shift "$(( $# - 1 ))"
printf '%s\n' "$1"

Likewise, the best way to get the most recently modified file (or directory) in bash would be to do

set -- /usr/bin/*
newest=$1; shift
for pathname do
    [ "$pathname" -nt "$newest" ] && newest=$pathname
done

printf 'Newest: %s\n' "$newest"

Change the -nt test to -ot to get the oldest (least recently modified) file.