Couldn't you look yourself up and adjust your playstyle accordingly? Like "oh, these guys will be expecting me to do X, but now I'm going to do Y instead to throw them off".
From my experience it's most useful for getting information on clear outliers. The ranking system might rank a very good player with terrible players until the ranking settles in. A few players are "boosted" by other players to reach higher ranks. In such situations it might be useful as you know that specific opponent on the other team is the one to watch out for or who to focus.
There is a lot of summary stats available, but the most useful one from personal experience is the win ratio. If the data tells you that one player on the other team wins 70 % of the games, then that's usually a clear indicator that the ranking of that player is most likely lower than it should be.
It might just be a better or worse player overall, so adapting to it might not be possible, except for knowing who to put pressure on.
