If this was a single-player game where you could be done after 1 playthrough, or if you legit had no way to avoid the attack (like, say, Dark Falz's Grants in original PSO as FOnewearl), or if people couldn't heal/cure/revive for you pretty much infinitely (if they don't, it's either on you or them, not the game), or if your rank went down right after the first death instead of 5...
You're expected to run this quest at least 50 times, possibly way more. Making mistakes and learning as you go is a natural part of every game, despite what some new age YouTubers will tell you about "trial and error" being "unfair", because every mechanic in every game is learned through trial and error. The main problem is about punishment and, unless you are solo, death is just not a harsh punishment in this game. And in the solo mode you're expected to have gained experience with all the enemies in multiplayer modes already. And if multiplayer on the highest difficulty is too harsh for you to learn anything, lower the difficulty until you're comfortable with the quest.
Also, as people have said before, there's really enough time to cure yourself with an atomizer (even without the ring) and walk to the other side of the platform. If you're too worried still, get the ring and learn to spam movement PAs, because they trivialise the section completely.
I do agree, however, that the current balance with a ridiculous amount of crutches like 3-second long guard frames built into attacks, lifesteal, 1 HP survival skills and potentials, infinite PP sources and ease of affixing tons of HP and PP is fairly absurd, but a lot of it was added to cater to the casual crowd post-PS4 release in Japan (I include Hero and everything that came with it into that category), and one-shots and ridiculous amounts of mobs were one way to restore a semblance of a game when those things trivialized all of the old encounters