The disbandment of Team Rocket began because of the battle wager between Ash and Giovanni, and it was actually Giovanni's own doing.
But when Ash heard Giovanni's proposal back then, he agreed without hesitation because, in his view, if Team Rocket were gone, the entire Kanto would become cleaner and more peaceful.
For this, Ash staked himself and battled Giovanni, ultimately emerging victorious.
Initially, the result was indeed good. After the fall of Team Rocket, Kanto became much more tranquil. The sudden collapse of such a large organization made all the evil organizations in Kanto feel on edge, fearing it was an action by the League, and worried they'd be the next target.
But later on...other organizations caught on and started establishing themselves in Kanto, using Team Rocket's disbandment as a foundation.
Before, with Team Rocket in Kanto, it was difficult for them to interfere, let alone establish bases in various Leagues like Team Rocket had done. They couldn't even take root in other Leagues.
Team Rocket could achieve such things because they traded with the League. What grounds do other evil organizations have? Did they really think the League was just idle?
But now, the situation has gotten out of the League's control. The disbandment of Team Rocket opened opportunities for other organizations. They used this as a springboard to grow and develop in other areas, especially Kanto.
Cynthia mentioned Team Galactic as the first they'd heard of, but it definitely wasn't the last to invade Kanto, and maybe not even the first.
The disbandment of Team Rocket unexpectedly ended up being detrimental to the entire League...this was something Ash never anticipated.
He couldn't help but recall what the experts in the group had said, that the disbandment of Team Rocket might not be a good thing. But at that time, the arrow was already on the bowstring, and he had no choice. It wasn't as if he could intentionally lose to the opponent, right?
Back then, Ash didn't understand what those experts meant. Why was beating Giovanni and causing Team Rocket's disbandment not a good thing? If something that benefits the entire League wasn't a good thing, what was?
Now he finally understood that what seemed to be a good thing on the surface might not be, and it could even result in worse outcomes.
Originally, Team Rocket's existence was something the League could control and even have a clear understanding of, despite Team Rocket gradually slipping out of control and creating terrifying entities like Mewtwo. Compared to other organizations, there was still some level of control.
But new incoming organizations hid entirely in the shadows, with enemies in the dark while the League was in the light, placing the League at a significant disadvantage.
Everything that happened to Little Lugia was just the beginning. There could be many hidden situations they haven't discovered yet.
"...I've heard that Team Magma and Team Aqua from the Hoenn Alliance, as well as Team Plasma from the Unova Region and Team Flare from the Kalos Region, have also come over."
Ash and the others: ...
Isn't this basically all the evil organizations from every region coming over?! Like the Johto Region, Kanto was also under Team Rocket's domain, so no other evil organizations came to Johto, but besides Johto, all other regions sent people here!
Although Ash didn't recognize any of them, since Cynthia mentioned them personally, it indicated that these evil organizations were all on the same level as Team Galactic.
They were all rushing over to claim this piece of the pie with the disbandment of Team Rocket!
On one hand, they could absorb Team Rocket's strength to bolster their own organizations, and on the other, it was the best opportunity to take root in Kanto and Johto. If they succeeded, Kanto and Johto would become the most chaotic regions in the League!
This genuinely turned a good deed into a terribly bad one, and it couldn't be any worse.
Originally hoping for Kanto and Johto to become the most peaceful League regions, now it seemed they were on track to become the regions with the poorest order—if that group managed to take root.
"Misty, Brock...did I make a mistake?" Ash's eyes showed confusion. If he hadn't blindly agreed to Giovanni's terms back then, wouldn't this have happened? Or was it perhaps better if he had lost that time...
"Not at all, Ash. Lorelei has already spoken with me about Team Rocket, and you did nothing wrong," Cynthia shook her head, proactively dispelling Ash's doubts before Misty and Brock could.
"If it weren't for you, the League wouldn't have discovered Team Rocket's wolf-like ambitions. Frankly, a Divine Domain-level entity under control could cause more harm than any damage done by those evil organizations. Don't mind Team Galactic claiming they want to capture the Sea God. If they actually encountered it, the Sea God could wipe them out with just a breath, so there's nothing to worry about on that front."
What made Team Rocket more terrifying than other organizations was their personnel spread across all regions and their research capabilities, even being able to create Divine Domain-level Pokemon. They even developed Pokeballs capable of forcibly capturing others' Pokemon. If these things became distributed downstream to all members of the organization, the consequences would be unimaginable.
Hence, Ash's wager with Giovanni to dismantle Team Rocket was not a mistake. In the long run, Team Rocket posed a greater threat than all other organizations combined.