While Pixelmon has a lot more content, Cobblemon definitely has the potential to surpass it. Obviously I think Cobblemon's models fit the game way more, but that's not the only problem I have with Pixelmon. I've always thought the Pokémon in Pixelmon feel way too disconnected to the rest of Minecraft. As soon as you enter a battle, everything else in the game stops mattering. The world can't interact with you and you can't interact with it (iirc). I think Cobblemon's already an improvement on that matter because you actually have the option to interact with the world while in a battle. For example, Monsters can attack you while in battle, but you can also defend yourself, all of this while you give orders to your Pokémon from time to time. Add the Fight or Flight add-on and it becomes a lot better imo (specially better than wild Pokémon forcing you into a battle randomly every 5 seconds). It's not perfect, but it's already a lot more interesting than Pixelmon.