Pokémon GO has gotten some excellent updates recently, notably the addition of a brand-new weather system that changes Pokémon spawns based on real-world weather. But there's still a weight around the endgame's neck, and there hasn't been much progress on fixing it since it was first unveiled to a tepid response. EX Raids are currently the only way in the game to complete your Pokédex by catching Mewtwo, the most powerful creature in the game. As such, they're the only true apex achievement. The only problem is that they're awful: access is controlled by rare invitations gifted randomly through opaque requirements, and they're largely inaccessible to most players. Most MMOs have an element of randomness, but the concept that an endgame goal would be controlled entirely by random action feels a bit ridiculous. And as I've said before, I don't think any measure of tweaking is going to save these things: if we want this to work, we're going to need to totally rethink how these raids are deployed.
The current system operates under a few assumptions. One, that raids are multiplayer events. Two, that EX Raids need to be more special than normal raids, not only because Mewtwo is a more valuable Pokémon but because the game needs some variation in how it presents raids. Three, that because these raids are much rarer, they need to happen at in a specific way in order to preserve their sense of occasion. Four, because the game takes place in the real world, there needs to needs to be a way to restrict access lest we cause a scene by allowing every trainer in a given city to show up and fight at a given time. And five, all of this needs to be done algorithmically because this is a giant game that takes place all over the world.
I think that we can preserve nearly all of this idea by throwing out just one of them: the idea that raids need to be multiplayer. Get rid of that, and the whole thing looks a lot easier.
The problem with random EX Raids invites right now is that most players don't get invites, that those who do might still not be able to make the raid, that the system right now favors spoofers or multiple account holders, and that the largely random catch system means that even those who get a coveted invitation and finish the raid might still not get the Mewtwo. Most of these problems stem from randomness, so let's get rid of that right out. That means that EX Raids will now be Pokémon GO's first quest, and that anyone who wants to try can fulfill the requirements and do so.
Here's how it might work: a player needs to be at least level 30 to qualify, but levels above that should make the eventual fight a bit easier. A player also needs to get X number of gold medals, enough to be difficult but not require you to get that impossible Dragon medal. You'd also need to get a gold medal at a gym, which you could then go designate as your home gym (this could be useful for all sorts of things). After that, you'd need to complete some kind of quest: finish one raid a day for seven days, catch X psychic Pokémon, evolve X Pokémon, etc. -- there isn't room for much in the way of interesting quests in Pokémon GO, but you could still have something. The process would take a week or so, or maybe even more. Once you did that, the leader of your team would give you some sort of summoning item, and you could use it to go to your home gym and summon Mewtwo for a one on one (or one on six, I guess). fight. It wouldn't be easy, but it would be doable for high-level players with the right team. If you failed to catch the creature, you could earn another summoning item and try again.
In the past Niantic has said that Pokémon GO isn't getting single-player battles because it's an MMO game, conveniently ignoring the fact that every MMO ever made has some sort of solo component. I've also said that the social experience is what makes Pokémon GO special, and that will still be true even if with a solo raid standing in as a top-tier goal. The key here is to introduce both variety and structure -- the current EX Raid system doesn't really do either.
Right now, Pokémon GO has no real endgame goal, not after you've hit level 40 and mostly not before that, either. It used to be completing the regional Pokédex, but the introduction of EX Raids has made that too frustrating and capricious to work, not to mention the fact that it becomes impossible once you've missed a single limited-time Legendary. Training up your Pokémon is nice, but raids are mostly about how many trainers you can get on board anyway. A top-tier solo raid and attendant quest would give players something to genuinely work for and something to organize the endgame grind. It would be a true test of the Pokémon team you've built and your mettle as a trainer -- just the kind of thing the endgame needs.