'Easy' doesn't mean 'kills itself like the Dun Scaith boss after enough time'.
I've done SusanoEX exclusively via learning PF, and after the last time I got informed I was obviously inside a raid bubble with no interaction with 'normal' folks started straight up FFLogs checking dudes between pulls to get a feel for things. Unsurprisingly, most of the raid community isn't hanging out in learning/clear parties at length, and it's largely the more casual player base. It's easy, even with non-raiders. It's not impossible to wipe, widespread failure to execute basic mechanics will probably eventually get you, and if everyone just keeps chain-dying there's a good chance you're going to enrage because Brink is a super hard damage penalty now, but it's nothing to do with raider privilege and doesn't preclude it from being a super straightforward fight.
Like, it can be both things. Susano EX (and doubly for Lakshmi, who doesn't even pretend to have a team component to her jump rope) can be a stand-out easy Primal in context of EX Primals thusfar, and groups can be doomed to wipe forever if everyone in them assumes they can be the one guy who doesn't mechanics that everyone else adjusts to.
Edit: I will admit to constantly bringing 1 other person with me, but 75% of every party is random dudes every time