PvP is the highest priority if you need gold for your guild or to level kingdoms. As you gain levels and team stats (i.e. global stat gains from levelling kingdoms) you will draw steadily stronger PvP opponents - and depending on the matchmaking luck you may get people way stronger than you. That makes it hard to win PvP even with a good deck (and yours sounds pretty sound for early to mid game). Bone Dragon (for example) is everywhere, and somewhat broken, and is tricky sometimes for end-game players to beat - with a traditional build trading spells and hits, you won’t beat them easily.
One option for getting lucrative PvP wins may be to move to a loop deck. Read my (long) post here: Ok i caved, suggest me a cheese BD team (but theres limitations) - #10 by Jainus on a good loop team that’s fairly easy to build and win with.
Other game modes are arguably better for getting souls, traitstones and general rewards. Do TH maps to get glory and a few gems. Make sure you’ve maxed all the quests and challenges for easy souls and stones.