that's all mighty fine, i still don't understand how a pokemon MMO would look like. how would group content work ? raids ? everyone taking turns at hitting the boss and you hope someone didn't disconnect or steve the stoner didn't fall asleep so you can actually progress in the fight ?
Look to Ni No Kuni, where you can equip pets and level them up, for an example of how you could do group content. Drops could include rare pets (that can be leveled) gear for the pets (Even though we're using the term pokemon here, use your imagination a little. You don't need to have animal based pets necessarily. You could do an entire game with robots which are fully modifiable and base parts are collectible, whatever, throw ideas at the wall), Im not sure "raids" would have to exist, but two person or four person dungeons could, with commensurate rewards. Grinding and looking for that rare spawn would be part of the game as well. I don't think turn based combat would be required necessarily. Do we have turn based PVP in modern MMOs? Of course not. Why would this have to be different? You control your pet while they battle. Your main character could be customized with equipment to min/max pet skill sets as well.
Much of the game would be based around collection and refinement of your "deck" of pets. Feasibly you could own every pet in the game in your storage (although, like bank vaults and the like, you could have the capacity for holding pets increase as one levels up their main character) but you would have to choose from a select subset of them at any one time, say 4 or 6 pets at maximum level, and those pets would need to be min-maxed according to their special abilities, statistics (which could vary from pet to pet even within a single pet type) and their equipment. You would need to find a good balance of pets so that you could handle any situation that's thrown at you. Since much of the gameplay would be based around elemental types (or whatever you would want to call them species types whatever) there would be some rock paper scissors involved.
The end game would be a lot of PVP and tournament play, but most of the things that define MMOs outside of raiding could be included, such as housing, exploration goals, tradeskills, even dungeons, etc.
Really, and I'm not saying this to be a dick, but the fact that you think that MMOs can only exist if they have raid content is an example of how hard the blinders of the MMO crowd have become. They really think the only game that can be made must have an end game consisting of an item grind that never ends.
I would posit the vast majority of people who would play an MMO
1. Hate the amount of time and effort raiding takes, in fact I would say this is a huge factor in the decline of MMOs as a genre that we see today. People have lives outside of gaming and when you have work and kids and shit, the raid game becomes far less important to you. Doesn't mean you wouldn't play an MMO that takes up less overall time and is less of an hassle to get involved in.
2. Hate raiding in general.
3. Don't want to play a game whose entire end game revolves around raiding, though raiding can certainly be a part of the game overall.
People want an end game, but that end game does not have to be raiding. WoW has sort of brainwashed us all into thinking that a raid based end game is the only thing that can exist and support a long term player base.
I posit that deck building and the strategy and collectible aspects as well as competitive tournaments with solid rewards (rare versions of pets, equipment, etc. with special models that will make your character distinct from others) would be more than enough to garner a large player base that would stick around, for a good long time. My evidence would be the existence of card collection games, the popularity of pokemon throughout the years, the success of games like Ni No Kuni, and the apparent popularity of the WoW pet battling system
No one will ever get 12 million players in one game again, but I bet you could swing a few million easy with this model. That would be more than enough to make mountains of money to swim in.