The simple reason people continue to fail the extreme primals as of late because the new players who never did it and the older players who never could do it think that somehow they can magically beat all the extremes through beating it overgeared and unsynced without bothering to learn the fights.
Also in regards to plumes.Except for the last phase on titan extreme always stack together.makes it easier to dodge them as a groups as opposed to having them all over the platform and getting in peoples way.