That's how I feel. Just about to fight the second gym leader and I've intentionally kept my party under leveled for her because the EXP share makes it so easy to level up with no effort. My team of 6 are all level 20 except for Magikarp which has the slowest XP growth requirements of my team and it's still level 17. Been using Repel intentionally just because by the time I got to the first gym, I was over leveled like crazy.
Also, is it me or are battles in the grass super easy to trigger? I had 4 battles in a row crossing 4 squares in Eterna Forest because I didn't have a repel on, and that was an irritating waste of time. If you don't start with Chimchar, you can literally catch a Ponyta outside of Eterna and go gib the gym trainers with it, along with the gym leader and it'll be level 17 before you fight for the badge.