Hmm...that actually is kind of a elegant solution in a way. Each of the "worlds" being more or less the consoles the games released on. The Gameboy/GBC, GBA/DS, 3DS, and Switch worlds.
I don't think it's perfect. And there are probably enough references to past gens and events in each of those generations. Plus, there is the problem of the Third Versions needing to be their own worlds anyway, within their own "Console Worlds".
And I don't think Looker and Anabel are from the world that Guzzlord destroyed. I think the Fallers are more like what happened to the Player in Legends Arceus. I think it's possible Arceus is the one sending more "advanced" Trainers to different worlds or timelines in order to fix problems that the locals aren't equipped to handle. Sending in ringers to solve problems that pop up. And eventually sending them back again.
So, I'm not convinced that totally works. But, I do like the idea. And I probably could be convinced if you have a bit more detail.
My personal theory is that Gamefreak sees every single individual playthrough of these games as their own "dimension". Every time the player chooses a different outfit or has a different party, it's a different world. We can kind of see shades of this with Rainbow Rocket. The past evil leaders all seem to come from worlds where they either won, or where the player never showed up. "Game Over" or "Unfinished" games, perhaps. Which means the Pokemon multiverse is basically infinite, because of all the different minor choices the players can make and who they choose to put on their team.
As for what Arceus is doing with the multiverse in the first place....well, my thoughts on that are LONG...and complicated.
But, basically, when Arceus hatched from his Cosmic Egg, the pieces of it's Shell turned into other Pokemon that Arceus never intended to create. These "Shell Giants" or "Shell Titans" probably want to re-combine with Arceus, and become the Cosmic Egg they used to be once again. The "Shell Giants" are the powerful "Gimmick" Pokemon that we've been dealing with since Gen 5. Kyurem, Deoxys (...maybe), Necrozma, Eternatus, and Terapagos. All of them are different types of "invaders" or "invasive species." All have crystalline attributes. All of them have craters associated with them crash landing on the planet. And all of them are responsible for "altering" Pokemon, in a similar way that Arceus is able to create Pokemon. A lesser ability, but still a powerful one. That's the story reason for all the gimmicks. Absofusion, Mega Evolution, Z-Moves, Gigantamax, and Terastallization are all these "Shell Giants" trying to gain influence over the Pokemon, in order to eventually gain influence over Arceus directly. Trying to get to Arceus by "infecting" the Pokemon with these changes and gimmicks.
So, Arceus is trying to limit the influence and spread of these "invasive species", by sending powerful trainers to catch and contain them. That's why there's Fallers. It's a way to quarantine and limit the spread of these "Shell Giants".
Threre's also something going on with certain Giant Trees that we should probably be paying attention to. And how the Crystals that are scattered around the various regions keep getting larger and larger as the generations go on. Both are probably signs of the "infection" getting worse, in different ways. There's also the Pokerus of it all. Pokerus has kind of disappeared in the latest games (for real world reasons)...but Alpha Pokemon are a similar concept (random stronger pokemon) with a similar symbol on their profile. Story-wise, I wonder if you could say that Pokerus was actually the first stage of what would become the Alpha Pokemon. But, that's more of a side tangent.
This is just a overview. If you want to read more, head on over here:
Only a handful really felt broken (looking at you especially, Rayquaza and Gengar). Some, like Garchomp, are even downgrades.
www.allspark.com
...I really need to write up a full, complete post about all this one of these days. Pictures and everything. I will say, I was sort of right and sort of wrong about the Prism Tower, given the way Legends Z-A ends. It'll be interesting to see if Prism Tower changes again, once the DLC is over. But, I was VERY wrong about Gen X, given the leaks.