You make a good point that for Champion Accounts, cards are really the worst rewards which is a problem.

The way I see it, this Soulbound Reward Card idea is an excellent opportunity to give SPS/Vouchers/DEC more use case. I would not mind a system where by default the cards are Soulbound and based on the amount of Staked SPS they have a certain chance to turn into real tradable reward cards. That crushes the bots that just extract value, gives the bigger players all reward cards just as they used to be and gives smaller players incentives not to dump the SPS they earn. It would be nice if this also came with the option the delegate SPS so investors that don't play get an extra return this way.

I also wonder what will happen to the rental market as it could collapse since reward cards have been a good incentive for players to rent more cards.

What I do wonder if this change to Soulbound reward cards will be a proposal or if the team just brute forces it into the game which pretty much would make the entire proposal system useless.

Regardless of what happens, I'm sure it will be done in a way that is reasonable similar to pretty much everything the devs have done in the past.