>>57290751DP (or rather "Pocket Monsters Diamond" as Masuda planned all the way back in Gen II) was designed to be the "ultimate Pokémon game". Ruby and Sapphire were named as such literally because they were stepping stones to Diamond in value, and if they couldn't name Gen III those names, it would hurt the whole naming scheme. Because they couldn't transfer Pokémon from the Game Boy to the GBA, he also had remakes of Red and Green in mind around 2000/2001.
And when you look at Diamond (and Pearl), you can see a few things.
>They carry over pretty much everything introduced in Gen III (Contests, Abilities, Natures, EVs, IVs, items, double battles, Vs. Seeker, wireless communications, etc.)>They reintroduce everything cut or mitigated by Gen III (day one backwards compatibility, day/night and time-based events, days of the week, online battling/trading, post-game content, etc.)>Were more comparable to Gen I and II in Pokémon availability than Gen III which die almost immediately upon reaching post-game >Include third version elements in the base game like events and animated sprites>Game Freak at their best region design with Mt. Coronet being their most ambitious dungeon and not having the glaring "17 water routes" issue of Hoenn>Sinnoh corresponds to "North" in the Spaceworld 97 demo, meaning they now had an "East" (Kanto), West (Kansai/Johto), South (Kyushu/Hoenn), and North (Hokkaido/Sinnoh)And we can see from the leaks just how ambitious they were being for DP, especially with background lore. Platinum is better, but it's built on DP's foundation.
