Only the linear JRPGs with set & designed party members have traditionally had a lot of party interactions. Non-linear open-world JRPGs tend to be as devoid of them as WRPGs.
SaGa, Etrian, several Dragon Quests, Metal Max, mainline SMT, and Pokemon essentially don't have party interactions in the ways that people are treating as genre norms.
SaGa, Etrian, several Dragon Quests, Metal Max, mainline SMT, and Pokemon essentially don't have party interactions in the ways that people are treating as genre norms.