That was a long read. Good thing I picked up yugioh instead of pkmn as a childhood anime. Reading from it I would drop out from sheer annoyance then I again I did get through Zexal.
So why am I talking about yu-gi-oh? Because yu-gi-oh is similar show as pokemon (20 min commercial, childhood nostalgia, kid show, ...) but better has a better sustainable model. So I want to use it as a reference for pokemon.
So as I said yu gi oh has a similar past as pokemon but they did one major thing different: they ended the story of yugi muto. By letting Yami duel yugi they created a powerful scene which not only allows the series to end but also symbolizes the growth of yugi and the journey he and Yami made.
So with no story left to tell what did yu-gi-oh. Tell a completely new story, with a new setting, new characters, ... . In first instance you would think this is the same as pokemon but yugioh managed to remove all the past baggage. No need to go over the top as in dragonball or do an awkward reset as in pokemon. You don't even have to completely follow the card game to try out some new elements.
That is the cycle of yu-gi-oh. They start the story from scratch to end with a ceremonial duel to cap off the series and then start over.
I think this could also work with pokemon. Start the series with a new start to explore new ventures. The games have done it already. However that requires the anime to A take a risk and B be creative and I already feel them shivering at the thought.
Alola was the perfect setting for this new main character but alas more Ash, so you won't get me even consider restarting the series.