By 2006, the mainline Pokémon formula was something I was starting to get burned out on. It's not that it's bad, per se, but by Gen 4 I felt like I was going through the motions. It wouldn't be till 2024 that I'd try out anything from Gen 5 to 7 because of this. (Happily though, I can say that doing so was worth it!) On its own merits, Diamond is still fine. I remember getting a few Badges & then just kinda calling it.