>>51625178>they might as well just replace him with some cheap Ash look-alike who is nowhere near different from himIf you grafted current Ash's personality onto a completely new character it would flop just as hard as Goh did.
People first like Ash because everyone, even dumb zoomer babies today, has seen the quirky OS anime where Ash became their window into the weird world of Pokemon.
The continue to like him because in a weird meta way, he has continued to go to different regions while not being tied to those region's canon. If he continues into the SS anime he'll be the only character to have all 4 gimmicks and rep a region he isn't even native to. He more closely mirrors his audience's personal experience than any other anime MC.
He's about as close to a Gordon Freeman character as you can get with a character who has an actual personality and identity distinct from the audience/viewer/player.