honestly, the continued existence of "the rival" just shouldn't even really be a thing. like, GSC is a direct sequel, it makes sense that it carries over and plays with some of these archetypes from the first games, but:
>rival who takes supereffective starter against yours
>evil team
>eight mono-type gyms followed by elite four
>mirrored legendaries
>magikarp-like that evolves into gyarados-like
It's all just symptoms of Masuda being a coward with no original ideas of his own cargo culting the first games because he was terrified of seeing it all collapse after being handed the reigns.