I understand that there's going to be a rather significant amount of refactoring for S3, especially if they want to decouple receiving card pack from answering issues, but coming up on 2 1/2 years is rather sluggish unless they intend to make a whole new browser-based game around the cards.
A Top-Trumps style system would be pretty cool though, where people could build 'combat decks' and challenge people similarly to the challenge system that is currently in place ig, but making getting the packs require playing TT games would put off collectors who don't want to minmax their decks to fight others, and just like passively collecting. Would give cards more intrinsic value though, could help to stabilise and stratify cards into price bands depending on their stats, cards could still have inflated values but it could encourage more movement on the market for actual purposes rather than just the chaotic swirling of inflation and subjective demand that is currently in place.
Or a Gwent style game pahah, maybe a championship.
Ooh - or if you had a Hearthstone-style game, where the 'play cost' of the cards are the populations, then they can battle using the number of 1% badges, 10% badges etc, the rarity determines the style of the card and you could add special flairs for things like 'Founder', 'Supporter', 'Easter eggs' and authoring badges. Maybe their attacks could be affected by their policies, so if a nation has WMDs it can use them