No one is questioning your skill at the game, but how accurate it is to the casual player.
I was trying to debunk the notion all you needed was "read a wiki" and stack "buffs" when obviously there's a lot more going on here. How can i take seriously a criticism of the game coming from someone making arguments like that. That's what set me off.
In terms of that approach working for the casual player, i was merely speculating given people say Scadutree upgrades make a big difference, though perhaps i was over estimating how much. It's worth point out though that the double katana guy manages to actually take over half of the boss life before the lighting phase begins, and his playing was rather sloppy. If he had done a perfect run on the non-elemental first phase, i don't think you would have seen the wind or frost phases in his video either. And i think FromSoft knows that people would try their best to just do as much damage as humanly possible during the easier first phase which might be one of the reasons they went to town with the elemental phases, knowing people would do anything in their power to cut those short.
If they wanted to prevent that they could have easily given the boss an actual second phase with an health bar refill. The fact they didn't means they at the very least expected people would put their all their efforts on a DPS race to see as little of the elemental phases as possible.
Again, I admit I may have a distorted view on what is average. But also is hard to explain then if players actually had builds comparable to yours, even if weaker but safer versions, why so many complained about the difficulty when a good build make them reasonable or even easy? I'm arguing that perhaps you may be putting too much faith on the average consumer. But again, I could be the one in the wrong here.
My build isn't actually good though, but it's not about the build anyway.
I think the complaint is not that the boss is hard as such, but that it is impossibly hard. Not so hard as to be impossible to beat, but i think people feel a lot of the time they get hit through no fault of their own. Making mistakes is one thing, getting hit because many times the boss does things that the player simply cannot react to is another. I think thast's basically the general complaint with this DLC.
Now perhaps i'm putting too much trust in FromSoft but i've always been of the opinion everything they do is calculated. True sometimes the occational jank creates unintended difficulties for the player but that's not the only issue with this boss because some dificulties appear to be fully intended, and if it's intented there must be a way. And often times i found that the "way" is an intended exploit you are supposed to use. That's been the major breakthrough that sets Elden Ring apart from Souls. While there were bosses in Souls that also were a puzzle you had to solve (like Artorias for instance), they leaned very heavily on this in Elden Ring, and i think they did so in part as a response to all the powerful tools they gave the player. In fact, you could almost say that because they gave the player things that seems almost unfair for the boss, they ended up giving bosses things that are unfair to the player in return.
In the case of this boss, you cannot say for instance that stuff like bleed or rot are "for try hards". If the boss is weak to those things it means the difficutly is balanced with those weaknesses in mind. You don't need to read a wiki either you can just try things out to see what works best. In my case i didn't read the wiki to know he was weak to fire. I tried out the same weapon with different damage types to see which hit the hardest.