True true... the pacing is a bit weird though, since you beat Erika, do the rocket hideout, then do lavender tower, then go back to fight team rocket AGAIN, before finally doing Sabrina's gym, or going south to Koga's gym.
That's a looong time between the fourth and fifth badge, with a lot of team rocket shenanigans in between, after which, they're barely heard from again, until the final badge