friend, I think youre in the minority with not wanting them to support eachother for one LAST splatfest after being at eachothers throats in the past (theres a lot of art on pixiv about the two supporting eachother for once, for once)
so I think its just you who wants them to be utter rivals, its not really their FUNCTION, sure, maybe for splatfests sometimes, but ORIGINALLY they were just newscasters and the agents in the storyline, thats all. If they were rivals why would they be doing ANYTHING together, why would they be together as the squid sisters idol group? They wouldnt if they hated eachother THAT squidding much.
so stop speaking for the entire fanbase when only a handful enjoys petty rivalry and the sisters being total utter jerks for no reason/an unhealthy relationship between the two partners