To me, the "whales" are just people who have invested the most in the game, and I think we kind of need people like that. Not sure how some people having far more cards than others affects the gameplay of people at lower levels who can't or don't want to invest thousands of dollars into the game.

Maybe the problem is that all levels compete on the same leaderboard. So the "champions" will always have whales amongst the ranks since they have the most powerful cards. Maybe there could be champions of bronze league, champions of silver, etc. etc. So people feel like there are attainable top goals for them. In reality, without at least spending some money on rentals, the actual Champion league or top of the leaderboard is simply (and understandably) unattainable. It's like skiiers of any and all levels all going down the same hill. Maybe we need some smaller hills.