It makes no sense to make Ash the "Strongest trainer in the world" if theres literally more of the Pokemon world to see. I could see if Journeys and Gen 8 was the last region ever, that would make sense. But there are more gym leaders who will probably destroy Ash's team for a few episodes before Ash pulls some dumb technique from his ass and beats them.
The whole anime is just a horrible SPEDfest for the severely autistic.