The detailed manpage is great. The more details the manpage has for each flag, the easier it is for me to find the flag I'm looking for by searching for related terms. Longer descriptions means a greater chance of my related search term hitting a relevant result.

Common flags and short descriptions of them can be found with `mpv --help` or `tldr mpv`

rsync is another example of a manpage I love. Very detailed means very useful. With a detailed manpage, I don't have to waste my time figuring out where the real manual is.