simply this...the story is centered around op people and op people realize that taijutsu isnt as effective on other op people....so they use ninjutsu.....while its true that the fights lack the depth and feel to them like the old fights, we would get sick of seeing them fight the same again and again...just look how tired we are of rasengan and susanoo spam....so simply the reason there arent many new fights like that is for 2 reasons....many of the main characters are not close range fighters, or its to preserve our memories.....im waiting for sasuke vs naruto rd 2.....(it should happen....)