I watch people stream MGS all the time. Why isn't there a leaderboard for it? I was pretty disappointed i couldn't find what the best times are for this game. :/

Is there a leaderboard somewhere else or a google doc?

There seems to be yes, https://www.metalgearspeedruns.com/ though its security certificate has expired so I doubt it's particularly updated.

We won't add leaderboards without either the people in charge of the existing leaderboard (if there is one) requesting it or otherwise the community requesting it, as it is the community that maintains the leaderboard, ofc.