For Pokemon fans who have spent years watching Ash travel through the various regions in the anime, Pokemon: Aim to Be a Pokemon Master has been an emotional series serving as Ash's final adventures in the franchise overall.

Source: https://comicbook.com/anime/news/pokemon-anime-team-rocket-split-explained/

If only Ash had the brains to do this to all of his Pokemon then he really would have become the Pokemon Master.

Source: https://gamerant.com/pokemon-ash-ketchums-best-pokemon-if-evolved/