They has a bunch of feedback about being more "moon" based, rather than elemental. So they tried out moonbeam.
We will see if it sticks or not.
As you showed, defenses is fairly balanced now.
To balanced offense, just have a 'spend a spell slot to deal more damage' in some form. (Would be OP if they got to match a Barbarian without expending slots).
So if not moonbeam, then something like elemental weapon, primal smite, haste, or higher CR creature.
Part of the problem is that 1/3 CR falls further behind as you go up.
I.e.
at level 6, your CR is 4 levels lower.
at level 15, your CR is 10 levels lower.
Maybe something like CR 1/3 your level + the spell slot level you expended.
I.e. at level 15, you have CR 5, and expend a 5rd level slot = CR 10