Actually this video makes no sense. He hates Ash but lets be honest. He was portrayed as Dumb in Indigo league and BW Agreed but nearly full of his video is filled with Original Series.
Here are some of my thoughts regarding his claims.
1) Ash Never wins a league- But he has been rather unfortunate than losing because of poor skills.
Indigo League- He lost because of disobedient charizard
Johto League- The match he lost was a very close one. It could have gone Either way.
Hoenn League- Another close battle which could have gone either way.
Sinnoh League- Freakin Tobias stopping Ash from winning his first ever league
Unova League- Ash was at an advantage as opponent had only 5 pokemon in his party but still it was down to 1 vs 1 and Riolu evolved.
So, he was unfortunate in most of the leagues.Many matches could have gone in his favour
2) Ash Doesn't Catch all of them. He has only 46/721
Why should he? i mean, i dont catch'em all.Its a waste of pokeballs.
The guy must remember that its an anime not a game. Assuming he catches all 721 would it be interesting?
Character development would suck.Also he wouldn't get time to train all the pokemon.A story without character development will be boring and will become stale.
Also we know what happened when he caught more than 5 mons.He did it twice, In Kanto and in Unova. Kingler, Muk and Toraus were overshadowed and had very less character development. Unova Sucked. He did not evolve any of his pokemon from first stage to last stage with the exception of Leavanny which is a bug and Unfezant which is a bird pokemon which fully evolves normally. Also he only caught 5 in Kalos and fully evolved them and he now has a powerful team.
3) He leaves all pokemon at oak's lab when he goes to a new region
As we all know anime also works as an advertisement for new games.The purpose of him going to a new region is to exhibit new mons and if he brings his pokemon to new region he will not be able to catch new pokemon.
He also wants to take it as a challenge. He might win if he takes his all time powerful team but he doesn't want it.
4) Ash hasn't progressed from the first episode
Tbh, he has. He is not the dumb kid he was talking about anymore.He knows how to bond with pokemon and understand their feelings.He builds strategies and comes up with new ideas.
5) Ash vs Red (Origins)
Yeah, Origins was a cool side series but it would have sucked if it was the main series.Reason, Red is not really challenged by any of the gym leaders and he beats them anyway.
The story is based on the game pokemon Red where your goal is to win. That explains why he wins, catches'em all.
Part two is coming soon since i didn't watch the full video.
Being a pokemon master is not just catching them all and winning leagues.Its how well you understand them and care for them. Its about being one with the pokemon.
Edit: Well he explained most of this anyway.