I think that if a player (or should we nowadays say "the bot of a player"?) is skillful enough to succeed in a certain league, they should also be able to earn the rewards promised by this league. Actually, if someone with cards of a lower level reaches the same rating like a player with cards of higher levels that is an indicator that they play the game rather well. I see no reason to punish good players.

Yes, I see a huge problem caused by bots, but in my opinion to 'punish' skillful players is not the solution of that problem.

Furthermore, some cards are simply not much better on higher than on lower levels (think at the chicken), and therefore I see no reason to put artificial pressure on uplevelling every single card.