you can say whatever you want but still, you need to "level up" again in those and the most efficient way to do it is litterally fate farm, dropping the items for relics step ? fate farm
duels ? those are fate too but you tackle them alone (and you need to participate in specific fate to be able to take them on)
i could agree on BA/CLL/DR part (DRS was a mistake imo) but you'll never make me believe that anything in field exploration couldn't be put in the open world (you know a part of the game that is lacking and ever more since field exploration exist)