how come there are no individual board runs?

My guess is all of the parties that have story modes do not have individual board runs, but I am not sure. I checked 4,5, and 7's pages, and they don't have individual board runs either.

maaannn

You can still run the game however you'd like! Even if there isn't representation of a certain category, you can put your own personal work in. If you're able to inspire others to run the game in the same fashion and there is an increase in runs of this type, it's not as unlikely for a leaderboard to be created for it anymore. Run the game, have fun, be passionate, and share your experiences with everybody!

okie

i know for a fact 7 has single board record on the site.

source: https://www.speedrun.com/marioparty7/individual_levels

Oh, shoot, I missed out on that. Good to know.