>>12199732Because if Ash actually got stronger, then Pokémon would be a Shonen at that point and they'd have to have other rivals that pull off major bullshit.
Imagine a rival winning with something more ass-pulley than "Aim for the Horn", Thunder Armor and Counter Shield combined.
Hell, imagine Ash actually climbing up in rank and building a reputation where other trainers seek him out for a challenge, causing him to question "Is it really worth being the best?"
That's too smart for the kids and it'll probably make their brains bleed, eyes melt and their faces burn. So instead Ash will be like Nobita -- he'll remain the same age for maybe 30 or 50 more years while GameFreak makes it perfectly clear the world around Ash's game proxy Red has progressed much farther than that. They will never let him grow up. Ever.
