Because their whole system is about a group of friends coming together, working together and beating a much stronger foe, If it is a jrpg with a part it inherently uses the power of friendship, even games like yakuza 7 uses the power of friendship, in order for a Jrpg to not use the power of friendship, you have to have there only be one person playable with no party at all or do like octopath did, the party is there only to be a mechanic, no one is involve with anyone else in their stories