>>49209221Hoenn is an awesome region aside from the abundance of water routes, with RS only being held back by a lack of content. I mean, compared to GSC, there was generally a lot less to do, and the big innovation introduced (double battles) felt very underutilized. But the core game was extremely strong and, in my opinion, did the best job of selling the idea that you were going on a grand adventure.
Emerald added exactly what it needed to. You had Gym Leader rematches, a new superboss, a bunch more double battles (and the concept was explored a bit more through double battles against two different kinds of trainers), and then the Battle Frontier provided a challenge to experienced players who nonetheless didn't really care about playing competitive.