The Pokeyman's world has been destroyed

I have a theory.

The accident with the bike? It put Ash in a coma. three days later he was found and pumped full of painkillers. This is why team rocket became less menacing. The drugs kicked in and stabilized his coma dreams, instead of being terrifying, they became idyllic, and he's able to live out his pokemon master fantasies.

It's also the reason that every time he enters a new region, virtually no one has heard of him, despite his conquests, and why givoanni leads team rocket. Ash has daddy issues, so he put his dad atop the evil corporation, and he just can't picture himself as famous, so he essentially adopts a new identity every few months.

It also explains a few other things, such as how a child can go off on his own in a world full of dangerous untamed animals, and why every pokecenter has the same exact nurse.
Brock is ash's repressed sexuality, he fell into the coma a virgin, and needed an outlet for it. since he can never experience it, brock must never succeed.
To further expand on this, one will note how misty, a tomboy, is another aspect of Ash's personality, his feminine side. the feminine side would obviously be upset at the womanizing side, which would keep a normal human being from acting like brock. This is why she constantly batters him.

I can explain the purpose of any character to ash's mindset within the coma to make it make sense.

It's the same thing as his community. Never experienced anything else, and couldn't at this point. He's only able to imagine landmasses besides his own because he used to dream about going to them and winning tournaments there. Also the reason Joys and Jennys are everywhere - those were just two figures he looked up to in his hometown so he projected them everywhere.
Team rocket is aspects of ash's personality that he has deemed "bad" james implied homosexuality, and jesse's vanity. You'll remember that meowth has the potential for rehabilitation, and doesn't want to be evil, so yet again this fits in with the confli\cting personalities theory.

Their methods of capture become more and more ludicrous ( and physically impossible) because ash is just a kid dreaming these things up.

The worldwide socalism can be explained if you once again realize that this is a dream world, he thought up a safe system of government that would run smoothly and keep the world going, allowing his adventures to work like they do.

and another thing.

Pikachu?

Pikachu obviously represents ash's Humanity, hence the episodes where they get separated, and ash wants desparately to find him, but for some reason cannot. Even team rocket is willing to set aside any differences to work together and find pikachu. They want to steal pikachu ( ash's humanity) and hand it over to his father. They will always be opposed because ash does not want to become anything like his father and no resolution can ever permanantly be reached. however he will temporarily reconcile with those aspects of himself in order to save his humanity from just becoming flat out LOST.
Max came with may, she played the ID with great aspirations, and he played the sensible Ego that "Session". They worked for a little while but ash, being a teenager eventually his sexuality had to come back into play. he kept reinventing himself and eventually Wrote new aspects, but his mind slowly brought back the old ones as a crutch to make the transition easier.
Also, why the elite four?

Why not one elite unbeatable trainer?

Because no person has one single psychological roadblock, and toppling all of them in one go would rend one's minds into shreds. I would assume that if he were ever to beat all four the coma would reverse itself.

Now it's time for Gary Oak.
Gary oak is what ash wants to be. He's wish fulfillment. he succeeded, and settled down to a normal life. ash needs someone to succeed in his world or he won't be able to validate it and will start questioning why he's where he is. it's a subconscious trap to keep him from becoming too aware of his situation. His mind must have figured out that awareness of the coma would snap him out of it, but it would cause major brain damage, so it took something the boy already loved and built a way out for him with it. however ash is too complacent to finally fight his way out of it, and cannot escape. this is why he keeps encountering legendaries, they're his mind's way of showing him he can do great things if he tries, and it's a way to encourage him to push forwards.

Dawn is ash giving himself a chance to love. since he already established misty as someone he's not likely to go anywhere with, he created a new super female, one that was more like him, and less violent all the time. ( you'll note that both may and misty had no tolerance for brock whatsoever whereas dawn seems to try and shrug it off.) Richie and his pikachu were another success story for ash, but he wanted one he could be closer with. One nearly identical to him. One that even used a similar roster to him.

Paul is ash's dark side, one that wants to push on even harder and harder, the part of him that will stop at nothing to escape this coma world.

The reason for the new rivals is that gary settled down, he's living peacefully, and to bring him out of that would be to supress part of ash's wishes.There's no way his mind would let that happen, so his personality fragmented further, producing dark (paul) and light (richie) versions of gary.
Mr.Mime is actually a stand in for ash's father, one that can't abuse him or his mom, because he is a pokemon, a peace loving creature that's oddly humanoid, but that can never hurt a human ( ash's trust is because he was never really hurt by a pokemon, so he sees them all as harmless, whereas in the real world they may be quite feral or vicious ( as seen in the early wpisodes), again falling back to the theory that the only real pokemon are the ones from the first season, and everything else is just further speculation coming from his mind on what new species would look like.)
And the movies?

Ash has been switched to a new treatment, and is adjusting to it, so his mind runs wild, allowing things to become grittier.

He releases them (his pokemon) because his mind is forcing him to let go of them. The second he raises an overpowered team, a tournament comes up, and after fighting his way through it he has to go to a new land for new challenges, but with an overpowered team, there won't be any challenges, and no way to motivate him further, part of ash wants to stay in the coma, and keep journeying.

The other part wants freedom, and to return to his real life, to finally become a real pokemon master. However if he's allowed to keep his powerful team there's no reason to meet and ame new pokemon, he'll lose interest, and the chance of becoming self-aware comes around again. so it's not that he gives them up, it's that he loses them, and unless he's desparate ( like with charizard) he can't get them back. it's basically his mind forcing him to deal with his issues.

Aah the reason team rocket's disguises are always believed. He knows it's them ( on some level), but chooses to ignore it, so he can better himself, in a sense escapist ash is sabotaging idyllic ash. So that there can be more conflict, and hopefully an eventual escape.

Oh there are real animals. But they don't matter to ash's psyche so they don't come into play much. if ash had loved puppies, everything would be about different breeds of dogs, and a dog fighting circuit.


But, as the series goes on longer, we've been seeing less realistic animals and more Pokemon.

Could this be a sign of his mind's deteriation? That, as he's in this coma, he's losing concepts of some animals and machinery and replacing them with Pokemon. It could explain things like electric pokemon working as power generators.