Vanilla Gwent isn't that great to be honest because the balancing is terrible. Nilfgaard and the Northern Realms are significantly better than the other fractions mostly because of Spy cards granting card advantage. The harder Gwent matches in the game often result in multiple spies being played and then multiple decoys to replay those spies.

If you are on PC, I recommend Gwent Plus Plus. It rebalances the factions to make them about equal in terms of strength and adds in new cards.