>>47674152>>47674152The level curve isn't really the problem. It's actually quite good, bit it's scaled about 30% lower than in other games. Players tend to have a personal dislike for this because the levels top out just before pokemon start getting their really cool lvl 50+ moves.
The real problem is the experience curve. The amount of exp attainable from trainers prior to the E4 is about half that of the previous generation owing to there being about half the trainers available to fight. This results in your team becoming under-leveled, and you have to grind wild pokemon that adhere to the new level curve.
The way to fix this is by using a team of 3 pokemon or by adding 1 to 2 pokemon to each pre-E4 trainer.