how could they keep insiting ash was 10 every new region arc

when they had dialog or visuals in episodes that contridict this
the first was in the pikachu and pichu short in the begining of the 3rd film were ash said it had been a year since he met pikachu
and then in battle frontier in the episode gathering the gang of 4 were ash said he had known pikachu, squirtle, bulbasaur and charizard for years

and then at least one or twice a region has said it been a long time since he saw someone or been some were and then there is the 3 to 4 months ash generally has to wait for a league to begin which extends his travels in a region for at least a year

oh and then in black and white we see the passage of time via the deerling when ash arrives in unova the deerling are pink meaning it's spring then later in the series we see green deerling which means summer then toward the end of the final season when ash leaves unova the deerling are pink again meaning a year had gone by

and then we have how long ash would have been stuck in kalos waiting for everything to be rebuilt after pretty much all of lumious city was heavily destroyed and that would take at least a year to get a majority of it fixed so we could say his stay in kalos was a year and half to 2 years

and then he had to be in alola for at least 2 years and then at least another year had to have gone by going by how old lei is when ash returns to alola in the first journey's season

and him and goh had to have been research fellows for at least a year and a half to 2 years by the end going by the season changes we see in kanto and a few other clues dropped by characters

and iris becoming the unova champion and we know that takes years going by backstories giving for other regional champs and elite 4 members
when she was still getting use to battling by the end of the unova arc and did not even seam to have any major clue what she wanted to do fully outside eventually becoming a gym leader which was already something she had no choice in