I want to point out that Xeno is VERY good at war, most wars you get in Duty Finder for normal content will not be able to pull this off. I play war myself, raid savage and ult on it (pld is my main though), and I know I would have a harder time doing what he did in that dungeon, if I even could do something like that. Doing something like that is knowing what buttons to press and when. Yes he says, just use bloodwhetting, but bloodwhetting alone will not completely help with wall to wall pulls. You need to use the rest of the kit too.
Further, I doubt a good number of these people that are striking have cleared savage or ultimates. This is not me trying to be mean, just pointing out a possible fact. Savage and Ults need healers to use their full kit, EVERY ogcd, EVERY skill. Ults to the point where the healing and mit need to planned out, and followed, or wipes occur. Even tanks' sustain/self healing will NOT completely mitigate the damage the bosses are doing. DPS sometimes need their self heals if they end up in a situation that they are too far from a healer. Yes, gear creep and level creep is a thing, which makes the older ults easier, but not to the point where healing from some source is not needed.
Lastly, don't you all remember The Burn, Gordias, or other such duties that were so difficult upon release that it took an extremely long time to clear or people would just leave/disband upon zoning in or failing more than a few times? I started playing during Stormblood release and I sure as heck remember The Burn, and the Mist Dragon just eaaaaaaaaaaaaaating people. I rememer Rabnastre on release and so many wipes just on the first couple bosses. If you complain the normal content currently is too easy remember those days and maybe try savage or ult. Or try a solo run challange.
TLDR: War that did this is extremely skilled, not every tank in normal content can do this. Be careful what you wish for and remember The Burn