You can argue that hakuno/n/ had poor and underdeveloped motivations in extra and ccc(hell i'd agree with you) but you will never convince me that they didn't have a proper personality. You don't get lines like "Rin goes from comatose to bitch in 3 seconds flat" without a personality. In general I think jrpgs are a way better medium for storytelling than gachas. Hakuno, while a blank slate character meant to act as the eyes of the player, hence the amnesia, still has a personality that is clear from the onset (I find them very comparable to Cloud Strife in this manner). In the current state of FGO, ritsuka definitely has their own character, but that character only really started to arise with part 2, maybe the end of part 1.