And what did you do to compensate?Yep. That is why we made Bards half-casters again akin to Paladins and Rangers. It avoid power imbalance like this.
I've seen Bards played as high as 15th level. Because of lack of damaging cantrips and otherwise less versatility than, say, wizards, they burn through their spells FAST - so can't keep up easily. Or did you make other casters half casters too?