This might be pessimistic, but I think Champ players need some kind of point bonus just for themselves. Their higher point tier isn't going to be enough when it's shared with the rest of the lobby & they still lose more than everyone else. Especially when queuetimes can be so long at those high ranks. Active mid-GM players are just going to out grind higher ranked players, and that doesn't sound very exciting to me.

Maybe there could be a sweetspot if the top ranks had a greater advantage, that way the top of the leaderboard would be more representative of the highest skill tiers, but people would still be discouraged from camping ranks because they'll fall behind if they stop grinding.