I saw something the other day that points to the fact that Giovanni may have been trying to capture or stop Mewtwo : he acquires the Silph Scope to capture Ghost Pokémon (one of few types Psychic was weak to), & when we stop him from doing that he attempts to get the Master Ball to get Mewtwo, but again we stop him.
That... makes no sense. For one thing, at least in the original games, the only Ghost-type line was part Poison-type, which Mewtwo slaughtered. (And was Team Rocket actually after the Silph Scope? It's been a while since I've played in Kanto, but I don't recall that being said.) And second, why bother trying to catch something that Mewtwo (isn't actually) weak against if you're going to have the Master Ball anyway? You wouldn't need to weaken it; the Master Ball is a guaranteed catch.
I'm not sure how Team Galactic is remotely close to interesting. Cyrus is the same old boring villain archetypal figure in which he wants to destroy and recreate the universe with no emotions. We don't even know how Cyrus arrived at that conclusion, and I think a tragic backstory, or at the very least, expansion into his backstory would help drive that point home more strongly.
But he did have a tragic backstory. You learn about it from his grandfather in the Battle Zone region area.
That being said, Cyrus's and Team Galactic's (by default) end goal makes no sense.
Well, the majority of Team Galactic either didn't even know what the end goal was, or believed it to be something that would benefit them, but they were a cult anyway.
Cyrus believed that emotions were the source of strife and suffering (and, is he wrong?), and sought to remove those things from existence. The myths of Sinnoh claim that spirit is integrally linked to time and space, and so by using Dialga and Palkia, he can break down the existing spacetime and replace it with one of his own design.
Not to mention, their grunts are incompetent morons who were in the shadows in regards to Cyrus not telling them what he was really after, so there's no real synergy between the team and the leaders.
But that was like... the whole point? Cyrus was only using his minions and followers as a means to an end; he didn't actually care about them, and intentionally hired idiots because they would do as they were told to do and wouldn't ask questions.
Cyrus didn't want to destroy and recreate anything
"Now, all will end. And everything will begin."
"With the power I wield, I will create an entirely new world! The incomplete and ugly world we have now can disappear. I am resetting everything to zero. Nothing can remain."
"Rather than repairing the world, you're going to destroy it for me! Do it. You inherit my legacy."
Prrrrrrrrrretty sure destroying the existing world was indeed on his to-do list.
(if he did, I'm sure he would have tried to capture Arceus)
Hardly anyone in Sinnoh, including Cynthia (who regularly studies mythology), even knew that Arceus was a
concept, let alone as much as its actual name. Besides, Dialga and Palkia would do just fine for his plan. He wanted to destroy and then recreate the universe; the universe is the spacetime continuum. Dialga and Palkia can control time and space, respectively. The only difference with Arceus would be that it can control both, as opposed to just one. But in Platinum, he summons both dragons at the same time anyway, so it makes no difference.
Anyway. Obviously, I'm a plot-oriented person, so eviscerating the games of their plots isn't something that I, personally, would jump for. It'd probably bore me, to be honest, but others are free to disagree. I am aware that the plot is not the priority, and I'm okay with that. In fact, as much as I like involved plots, I already don't expect a whole lot from the games' story content, which is probably why I tend to be more impressed when they go for things like the Looker Bureau and ORAS' storylines.