>>456113902D games USUALLY had unique Sprites for every gen (sometimes even during a single gen), which made the Pokemon much more fun to collect again and again, while 3D games were always the same models over and over again, to "future proof" pokemon (which seemed like a reasonable explaination, giving how we get more and more different pokemon, but they completely dropped the ball with Dexit just 2 Gens after that).
Also the games got WAY more handholdy
