It's not so much about the cards primarily, but the player base. The game will need to sustain a reasonably large player base to cover what will be millions of cards in existence.

As with everything, there will be a handful of whales and the rest will be minnows. It'll be up to the game developers to find ways to keep the minnows engaged while the whales sweep all the daily prizes (at least most). Because no matter how good your strategy is, a level 2 deck will be weak against a level 10 deck.

It'll be a fine balancing act for the devs. The 80/20 rule applies here like everywhere else. This is a business, and 80% profits will be earned from 20% of the customers. But you still need those other 80% customers otherwise you will not have a business.

If they can do it, get the balance right - and keep players - then this game will be massive and the card values will take care of themselves.

Just my 2c
☺