I would say that fits the historical\mythical berserker pretty well (except for the accuracy part). They were scary because they were hard to put down, even in situations where anyone else would be "this fight is going bad, time to make a break for it",
I hadn't thought of it that way.
To me, the image of an undying berserker is one who has taken arrows and axe blows beyond the point where they should be dead, but they're still up. And that image says, to me, that those hits are still fully effective. After all, if they were resisting the damage, then they wouldn't actually look like they
should be dead yet. If someone of a given power level can normally absorb 100 damage before dying, then something spooky is going on if they've taken 130 and are still coming. But in this case, with resistance to damage, the berserker has only absorbed 50 damage, so they
shouldn't be dead yet, and there's nothing spooky about that. The level 11 ability, where you reset to 1 when you would otherwise drop to zero, is a better reflection of that image.
That could just be a difference in how Hit Points work between editions, though. I still don't have a solid idea of exactly what Hit Point damage represents in 5E, to nearly the same degree as everything made sense in 3E.
It could also be a change in lore, though. I know that 4E added a magical aspect to barbarians, and some of that carried over to 5E, so maybe I'm imagining it wrong and they really are supposed to be possessed by a magical entity that protects them with a glowing energy barrier or something. That would explain the mechanics, in which case the only disconnect is that I'm picturing the wrong image.