Most JRPG have absolutely zero amount of "roleplaying" (the important part in "RPG". There are predetermined characters that you can't change, a predetermined story that you can't change, and absolutely no choice ever that actually affect what happens in the game.
There is often a marvelous world to see, and the storytelling is more often than not quite stronger than in western RPG, but that's "adventure", not "roleplay".
Not really Akka, just take example breath of fire 2, you can actually change the course of the story, you can chose to actually save the world or to ruin the world instead, there are 3 types of ending in breath of fire 2, also in breath of fire 3 you been given similar option.
How about Chrono Trigger? there are 10 types of ending that you can achieve depend on when and how you save the world from Lavos. Compare to that with Morrowind, even though Morrowind seem to have an open world and many side quest, but the main storyline is monotonous, the aim is singular also the end which is: you know how to kill dagoth ur and you kill it, and there is only
one way to kill it.
In final fantasy 7, you can have an optional character like Vincent or in Chrono Trigger you can chose to either defeat Magus or take him in your party. And you can custom your character in final fantasy 7 by your chose of weapon and materia.
I rather try to differentiate what is rpg from adventure game or mmorpg, by strong storyline, more interactive world, levelling system, weapon and equipment, and storyline must be put as priority than building character strength, fighting and solving puzzle (which in mmorpg and adventure game these are the main part of the game, a tiring part of these genre is that in my point of view).
Mostly in adventure you just solving puzzle to be rewarded with another puzzle, or in mmorpg, you fight through a dungeon just to be rewarded by another long boring dungeon, but in rpg you pass a puzzle and being reward by finding a new city, a new character, or progressing the storyline or you gain more intimacy with other character in your party.
While in Bethesda game compare to JRPG you have a lack of intimacy with the npc that you are dealing with, the character is so wide and colossal but without depth. But again you still categorize it as rpg Akka while Jrpg can be more rpg than Morrowind, I'm sorry even though I'm a huge elderscroll fans, but truth is the truth, I love truth more than I love elderscroll.
I can accept (because I understand) even though not fully agree civver definition of rpg, but yours definition I hardly agree with that. JRPG especially the oldschool one is the best rpg the market ever offer.