Why does Ash release so many of his Pokémon in the Anime?

Question

I hear he even releases his Charizard!...

Answer 1

He releases them so that he can A) get new Pokémon from the new region, or B) for story purposes. In fact, Ash actually releases very few of his Pokémon. The majority of them are sent to Professor Oak's lab (Bulbasaur, Tauros, Heracross, Infernape, Sceptile, Snivy, etc.)

Some go their own ways and are "released" but sometimes come back to Ash (Squirtle, Goodra, Lapras, Butterfree, ect.)

Finally, occasionally Ash leaves Pokémon in training. (Charizard, Primeape, Gliscor, etc.)

TL;DR Ash doesn't release many Pokémon, instead he sends them to Oak or leaves them with other Trainers. He leaves his team behind each region so that he can start fresh with all new Pokémon (with the exception of Pikachu and Aipom)

Here's some information on Ash's Pokémon's whereabouts.

Answer 2

Ash has actually only released five Pokémon in the entire anime. This is mainly due to the fact that he is constantly traveling to new regions, and has a limited amount of Pokémon he can keep on his team. Instead of keeping them in an electronic box, he probably believes that it is better for them to return to the wild.

Source - http://bulbapedia.bulbagarden.net/wiki/Released_Pokémon

Answer 3

Ash wants the best for his Pokémon in the anime and if they are better off being released or given away he is a nice enough trainer to give them what they want.

hope I helped !

• Dedenne :)