The only reason the level caps were removed was to drive more sales by increasing the Pay2win allowing players who want at the lower level to buy their way up and giving players who play according to their budget a bad time hitting a wall as they quickly just face higher level cards.
The game is at its most fun when everyone is on a level playing field, it's tricky though as both have a good and a bad side. Something out of the box might be needed to really fix the ranked play.
Why not have a system where all cards both players in a battle own are available to both. when a player picks a card that only the opponent owns, part of the earnings in case he gets a win will go to the opponent. This way there is always a fun level playing field on each battle and fair earnings based on assets held even when a player loses. No level limits would be needed that way even though the idea would likely need some serious tweaking still.