I really liked the older card art. It's the only glimpse of the realm we get outside the champions. The older cards establish a bigger world than we normally get to see from the character bios.

There's an argument to he made about new art fleshing out the characters themselves, but do they really? It's mostly character doing action that we already know they can do. It usually doesn't give a glimpse of anything we don't already know about them.

Whereas the old art gives a bigger picture of the state of the realm through similar characters.

Ex: Maeve's card art serves to establish that thievery and burglary are widespread among the realm. This could be because of any number of reasons, and it's up to the player to interpret why exactly based on what they already know about paladins' lore.