At the end of the day, I think that's all we can really hope for.I do not care either way. I just want a rival I'd like to beat, and one which has some decent characterisation and development.
An idea I've come to take a liking to would be a sibling rivalry. I feel like we've played the childhood friend rival antic for so long now, that I wouldn't mind trying something new, and a sibling rivalry could be just that. I can already picture the constant teases, the sibling squabbles coming from our older sister or brother. Then there's a certain taste of sweet satisfaction that comes from beating your older sibling every time. Oh joy! However, since in my head I picture the sibling to be older, then a childhood rival who's starting their journey at the same time as the player could probably still be used in this situation.