If you’re on macOS, you can open man pages in a separate, nicely formatted, window by using the x-man-page URL scheme.

Typing x-man-page://ls, however, isn’t super convenient. This script lets you type xman command_one two... and open each page in a separate window. If it can’t find the command you asked for, it prints a message to stderr. Enjoy!
#!/usr/bin/env zsh
function xman() {
for i in "$@"; do
if [ $(command -v $i) ]; then
open x-man-page://$i
elif; then
printf "Can't find command: %s\n" "$i" >&2
fi
done
}