I felt that other Final Fantasy games could have benefited greatly from the five person party concept.

I remember constantly getting annoyed in later games when the storyline would come up with an excuse for a party member to not travel with you, or for the party to split up constantly, just because the party was at its limit of four — or later, three — characters. I think I would have been more attached to a few characters in Final Fantasy VII, for example, if I had been allowed to choose five characters in combat or if the story chose which characters are acceptable to be in the party for me at more points.